Search for nearby stars among proper motion stars selected by optical-to-infrared photometr

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大学英语精读第6册课文全文翻译-中英对照

Some scientists working on the question of extraterrestrial intelligence, myself among them, have attempted to estimate the number of advanced technical civilizations -- defined operationally as societies capable of radio astronomy -- in the Milky Way Galaxy. Such estimates are little better than guesses. They require assigning numerical values to quantities such as the numbers and ages of stars; the abundance of planetary systems and the likelihood of the origin of life, which we know less well;and the probability of the evolution of intelligent life and the lifetime of technical civilizations, about which we know very little indeed.
In the last few years -- in one-millionth the lifetime of our species on this planet -- we have achieved an extraordinary technological capability which enables us to seek outunimaginably distant civilizations even if they are no more advanced than we. That capability is called radio astronomy and involves single radio telescopes, collections or arrays of radio telescopes, sensitive radio detectors, advanced computers for processing received date, and the imagination and skill of dedicated scientists. Radio astronomy has in the last decade opened a new window on the physical universe. It may also, if we are wise enough to make the effort, cast a profound light on the biologicaluniverse.

山东省泰安市岱岳区2021-2022学年八年级上学期期中英语试卷(Word版含答案)

2021-2022学年山东省泰安市岱岳区八年级（上）期中英语试卷（五四学制）一、完形填空阅读下面短文，掌握其大意，然后从每题所给的A、B、C三个选项中，选出能填入短文相应空白处的最佳选项，。

1．（10分）One day，a boy had a fight with one of his classmates.Then he went to his grandfather and told him his story （1）." He is really bad" the boy said，" and I hate him."The grandfather said，"Let me tell you a story.When I was a boy，too，sometimes I hated others for what they did.But hate will make you feel （2）.It doesn't hurt your enemy but only hurt（3）.As the boy （4）carefully，the grandfather went on，"There are always two tigers inside my heart.One is （5）and kind.He gets on well with everything around him .But the other is bad and unfriendly.He is full of （6）.Even the smallest thing will make him angry.He fights with everyone all the time，and for no （7）.He can't think carefully because he always hates others.It is （8）to live with these two tigers inside my heart.They both try to control me.The boy looked into his grandfather's eyes and asked，"Which tiger always controls you，grandfather？"The old man said slowly in a （9）invoice，The one that I feed.I always feed the good and kind tiger，so I never hate others and （10）get angry now.（1）A.happily B.softly C.angrily（2）A.happy B.tired C.interested（3）A.myself B.yourself C.himself（4）A.listened B.felt C.talked（5）A.dirty zy C.good（6）A.anger B.hope C.fear（7）A.money B.time C.reason（8）A.necessary B.difficult C .important（9）A.sad B.serious C.shy（10）A.always B.sometimes C.seldom二、阅读理解（本大题共两小节，每小题8分，满分30分）2．（8分）阅读下列短文或图表，从每题所给的A、B、C、D四个选项中，选出最佳选项。

SSSPMJ0829-1309 A new nearby L dwarf detected in SuperCOSMOS Sky Surveys

a r X i v :a s t r o -p h /0208433v 1 23 A u g 2002Mon.Not.R.Astron.Soc.000,1–4(2002)Printed 2February 2008(MN L A T E X style ﬁle v2.2)SSSPM J0829−1309:A new nearby L dwarf detected inSuperCOSMOS Sky SurveysR.-D.Scholz,1,3⋆H.Meusinger 2,31Astrophysikalisches Institut Potsdam,An der Sternwarte 16,D–14482Potsdam,Germany2Th¨u ringerLandessternwarte Tautenburg,Sternwarte 5,D–07778Tautenburg,Germany3Visiting astronomer,German-Spanish Astronomical Centre,Calar Alto,operated by the Max-Planck-Institute for Astronomy,Heidelberg,jointly with the Spanish National Comission for AstronomyAccepted ...Received ...;in original form ...ABSTRACTThe SuperCOSMOS Sky Surveys provide a complete coverage of the Southern sky in three passbands (photographic B J ,R and I )and at diﬀerent epochs (Hambly et al.2001a,b,c).These data are the basis for a new high proper motion survey which aims at ﬁnding extremely red nearby dwarf stars and brown dwarfs.One of the ﬁrst can-didates,which is relatively bright (I =16)but very red (R −I =2.8,B J −R =3.6),was detected in the equatorial zone by its large proper motion of 0.56arcsec/yr.Spectroscopic follow-up observations with the 2.2m telescope of the Calar Alto Ob-servatory classiﬁed this object as L2dwarf very similar to the ﬁrst free-ﬂoating L dwarf Kelu 1also discovered in a proper motion survey by Ruiz et al.(1997).If we assume SSSPM J0829−1309to have the same luminosity as Kelu 1,we get a distance estimate for the new L dwarf of about 12pc since it is about one magnitude brighter than Kelu 1in the SSS I and R bands.This makes SSSPM J0829−1309one of the nearest objects of its class,well suited for detailed investigations.We present a brief overview of all known nearby (d <20pc)southern L dwarfs and give ﬁrst proper motion values for DENIS-P J0255−47and SDSSp J1326−00and an improved proper motion for LHS 102B.Key words:surveys –stars:distances –stars:kinematics –stars:late-type –stars:low-mass,brown dwarfs –solar neighbourhood.1INTRODUCTIONOnly ﬁve years ago,the ﬁrst ﬁeld L dwarfs were discovered in a proper motion survey using ESO Schmidt plates (Ruiz et al.1997)and in the DEep Near-Infrared Survey (DENIS)(Delfosse et al.1997).In the following years,the new spec-tral type ”L”was deﬁned using the rapidly growing number of discoveries from the 2-Micron All-Sky Survey (2MASS)(Kirkpatrick et al.1999)and from DENIS (Mart´ın et al.1999).Most of the additional L dwarfs found since then are from 2MASS (Kirkpatrick et al.2000;Reid et al.2000;Gizis et al.2000)and from the Sloan Digital Sky Survey (SDSS)(Fan et al.2000;Schneider et al.2002;Hawley et al.2002).The colour-based search for L dwarfs with DENIS,2MASS and SDSS data has increased the sample size to more than 200,where the majority of the objects lie at dis-tances larger than 25pc,the limit of the Nearby Star Cata-logue (Gliese &Jahreiß1991).Nearby L dwarfs,suitable for⋆E-mail:rdscholz@aip.dedetailed follow-up observations,have also been found (see the list of Kirkpatrick et al.2000and references therein).However,many nearby L stars are still waiting to be dis-covered according to the predictions on their number den-sities from observations (Reid et al.1999;Gizis et al.2000)and theory (Chabrier 2002).The number density of L dwarfs (L0.0-L4.5)alone is expected to be around 0.002per cubic parsec (Gizis et al.2000),corresponding to about 70objects within 20pc.The completion of the census of L dwarfs in the Solar neighbourhood is important for in-vestigations of the star formation process,the stellar and substellar luminosity function and the initial mass function.As demonstrated with the recent discovery of three nearby L dwarfs in the Southern sky (Lodieu et al.2002),the SuperCOSMOS Sky Surveys (SSS)(Hambly et al.2001a,b,c)provide an eﬀective tool to ﬁnd nearby extremely red and low-luminosity objects via their proper motion and photographic colour.The SSS cover the whole Southern sky with scans of UK Schmidt Telescope (UKST)plates in three diﬀerent passbands (B J ,R,I )and at diﬀerent epochs with2R.-D.Scholz&H.Meusingeradditional scans of ESO Schmidt plates.Since practically all very nearby stars(d<10pc)in the Nearby Star Cat-alogue(Gliese&Jahreiß1991)have large proper motions (µ>0.18arcsec/yr,i.e.the limit of the New Luyten Two Tenths(NLTT)catalogue,Luyten1979-80),we can expect large proper motions for all nearby L dwarfs as well.The reason for the non-detection of L dwarfs among the NLTT stars is the lower limiting magnitude of theﬁrst Palomar Observatory Sky Survey(POSS-1)used by Luyten,com-pared to later Schmidt telescope surveys(POSS-2,UKST, ESO).UKST and ESO Schmidt plates are much deeper with limiting magnitudes of B J∼23,R∼22,I∼19(Hambly et al.2001a).It was thus possible toﬁnd theﬁrst free-ﬂoating L dwarf in the Solar neighbourhood,Kelu1with R=19.7,I=17.1(SSS magnitudes)as high proper motion object on Schmidt plates(Ruiz et al.1997).Trigonometric parallax measurements(Dahn et al.2002)have shown this benchmark L2dwarf to lie at a distance of19pc.In this paper,we announce the detection of another nearby L dwarf using the proper motion search technique. 2FINDING NEARBY L DW ARFS IN SSSIn order to estimate the chances toﬁnd nearby L dwarfs using SSS data,we have looked through the list of known objects(d<20pc)in the southern sky.Surprisingly,all known L dwarfs could be identiﬁed at least in the I band data of the SSS,except one object,for which no I plate measurement was available(Table1).This does not mean that we are able toﬁnd all these objects in a proper motion survey based on SSS,since we need measurements at several epochs for that task.Since all early L dwarfs(<L5)with d<20pc were detected in both R and I data,there is a good chance to discover this class of objects as proper motion objects if the epoch diﬀerence is not too small.The epoch diﬀerences between R and B J plates are typically10-15years.Those between R and I plates are smaller but with at least a few years in manyﬁelds still useful.Even for late L dwarfs within20pc appearing only in the I band data,there is the chance toﬁnd them in the overlap area of the Schmidt plates of diﬀerent epochs.Former attempts to detect L dwarfs in a proper motion survey based on the APM measurements of B J and R plates(Scholz et al.2000) did not lead to success since only early L dwarfs may show up in the B J band and the search area was restricted to a few thousand square degrees.There are diﬀerent possibilities to use the SSS data in a search for extremely red proper motion objects.In Lodieu et al.(2002),the basic search strategy started with looking for objects in the SSS catalogues which were not matched with a corresponding object in a diﬀerent passband to within a nominal search radius of3arcsec.Here we used the opposite strategy:in order toﬁnd nearby brown dwarf candidates,we set the conditions that1)an object was measured in all three passbands within a matching radius of6arcsec,2)the SSS computed proper motion(obtained from comparison of B J and R plates)is larger than100mas/yr,3)the object has star-like image parameters and4)the colours are extremely red,i.e.B J−R>3and R−I>2.The proper motion determination was then improved by further positional in-formation from the I plates and from2MASS(if available).Only the equatorial zone(−17◦<δ<+3◦)suitable for follow-up observations from Calar Alto was included in the search.The target of the present paper was selected as one of the most promising candidates in that search.It is called SSSPM J0829−1309since it was found via its proper motion in SSS data(see Table1).All measured proper motions of the objects in Table1 are larger than the NLTT limit of0.18arcsec/yr.Proper mo-tions obtained by Dahn et al.(2002)are much more accurate than the SSS based proper motions in Table1.However,for objects not included in Dahn et al.(2002)the use of SSS data allowed aﬁrst proper motion determination(DENIS-P J0255−47,SDSSp J1326−00)or led to an improved proper motion(LHS102B).3SPECTROSCOPIC DISTANCE ESTIMATE Spectroscopic follow-up observations were carried out with CAFOS,the focal reducer and faint objects spectrograph at the2.2m Calar Alto telescope.The grism B-400was used with a wavelength coverage from4000˚A to10000˚A.The combination with the SITe-1d CCD(0.53arcsec per pixel) yields10˚A per pixel.A slit width of1arcsec was used.The exposure time was45minutes both for SSSPM J0829−1309 and for Kelu1,23minutes for2MASS J1439284+192915and 6minutes for LHS2924.The spectra of SSSPM J0829−1309 and the comparison objects were taken under very similar atmospheric conditions and at comparable airmass.Wave-length andﬂux calibration was done under MIDAS using the Calar Alto standard reduction procedure SPECTRUM (written by K.Meisenheimer).The wavelength calibration was checked by means of night sky lines.The resulting spectra of SSSPM J0829−1309and three comparison objects are shown in Figure 1.We classify SSSPM J0829−1309as an L2dwarf due to the similarity of its spectrum with that of Kelu1(decreasing strength of TiO and VO absorption),which can also be seen if com-pared to the higher signal-to-noise spectra of Kelu1shown in Ruiz et al.(1997)and Reid et al.(2000).There are no2MASS magnitudes available for SSSPM J0829−1309.The distance estimate has therefore been obtained from a comparison with the photographic SSS magnitudes of Kelu1,for which a trigonometric parallax (d=18.7pc)has been determined by Dahn et al.(2002). Our target is roughly one magnitude brighter in both R and I so that we get a distance estimate of approximately12pc assuming the same absolute magnitude as for Kelu1.We have also obtained a higher resolution spectrum of SSSPM J0829−1309using grism R-100(2˚A per pixel)with 1hour exposure time.Low signal-to-noise features in this spectrum are consistent with Lithium absorption(at6708˚A) and Hαemission.This interpretation,if true,would make SSSPM J0829−1309a brown dwarf similar to Kelu1,but a conﬁrmation by a higher signal-to-noise spectrum is needed. 4CONCLUSIONSWe have discovered one of the nearestﬁeld L dwarfs, SSSPM J0829−1309,which we classify as L2dwarf similar to Kelu1.Based on the comparison of SSS magnitudes ofSSSPM J0829−1309:A new nearby L dwarf detected in SuperCOSMOS Sky Surveys3 Table1.SSS proper motions and photometry of SSSPM J0829−1309compared to all known nearby(d<20pc),southern L dwarfs.1SSSPM J0829−1309082834.11−130920.12001.28−565±13+4±2122.5818.8316.01L212 2SSSPM J0109−5101010901.29−510051.11990.80+207±04+94±1121.1918.2114.81L213 3Kelu1130540.18−254106.01998.41−289±14−24±1319.7317.11L219 4DENIS-P J1058−15105847.84−154817.51998.23−287±73+63±3620.3017.63L317 52MASSW J2224−01222443.82−015852.51998.77+533±38−910±3120.6518.40L4.511 6LHS102B000434.66−404401.61996.87+648±13−1476±0519.6116.88L510 7SDSSp J0539−00053951.99−005902.01998.83L514 8DENIS-P J1228−15122815.23−154734.21998.25+133±58−242±0120.5917.72L520 92MASSW J1507−16150747.70−162738.51998.34−137±17−908±0119.2316.14L57 10DENIS-P J0205−11020529.35−115930.41998.60+473±02+38±12517.93L720 11DENIS-P J0255−47025503.59−470050.91998.93+997±28−591±1620.1017.00L85 12SDSSp J1326−00132629.83−003831.21999.09−268±...−1004±...18.33∼L8184R.-D.Scholz&H.MeusingerFigure 1.Spectrum of SSSPM J0829−1309in comparison to those of other late-M andearly-L dwarfs.All spectra were obtained with CAFOS at the2.2m Calar Alto telescope(Fλnormalised at7500˚A).Spectral types of the comparison objects are from Kirkpatricket al.(2000)and Reid et al.(2000).Note the disappearance of the TiO band(7053˚A head,degraded to red)and the VO bands(broad trough∼7334–7534˚A and∼7851–7973˚A)fromspectral type M9to L2(Kirkpatrick et al.1999).based on observations made with the2.2m telescope of the German-Spanish Astronomical Centre,Calar Alto,Spain. We would like to thank the staﬀof the Calar Alto observa-tory for their help during the observations.REFERENCESChabrier G.,2002,ApJ,567,304Dahn C.C.,Harris H.C.,Vrba F.J.,et al.,2002,AJ,in press(astro-ph/0205050)Delfosse,X.,Tinney,C.G.,Forveille,T.,et al.,1997,A&A, 327,L25Fan X.,Knapp G.R.,Strauss M.A.,et al.,2000,AJ,119, 928Gizis J.E.,Monet D.G.,Reid I.N.,et al.,2000,AJ,120, 1085Gliese W.,JahreißH.,1991,Preliminary Version of the Third Catalogue of Nearby Stars,computer-readable ver-sion on ADC Selected Astronomical Catalogs Vol.1-CD-ROMGoldman B.,Delfosse X.,Forveille T.,et al.,1999,A&A, 351,L5Hambly N.C.,MacGillivray H.T.,Read M.A.,et al., 2001a,MNRAS,326,1279Hambly N.C.,Irwin M.J.,MacGillivray H.T.,2001b, MNRAS,326,1295Hambly N.C.,Davenhall A.C.,Irwin M.J.,MacGillivray H.T.,2001c,MNRAS,326,1315Hawley S.L.,Covey K.R.,Knapp G.R.,et al.,2002,AJ, 123,3409Henry T.J.,Ianna P.A.,Kirkpatrick J.D.,JahreißH.,1997, AJ,114,388Kirkpatrick J.D.,Reid I.N.,Liebert J.,et al.,1999,ApJ, 519,802Kirkpatrick J.D.,Reid I.N.,Liebert J.,et al.,2000,AJ, 120,447Lodieu N.,Scholz R.-D.,McCaughrean M.J.,2002,A&A, 389,L20Luyten W.J.,1979-1980,New Luyten Catalogue of Stars with Proper Motions Larger than Two Tenths of an Arc-second,Minneapolis,University of Minnesota,computer-readable version on ADC Selected Astronomical Catalogs Vol.1-CD-ROMMart´ın,E.L.,Delfosse,X.,Basri,G.,et al.,1999,AJ,118, 2466Reid I.N.,Kirkpatrick J.D.,Liebert J.,et al.,1999,ApJ, 521,613Reid I.N.,Kirkpatrick J.D.,Gizis J.E.,et al.,2000,AJ, 119,369Ruiz M.T.,Leggett S.K.,Allard F.,1997,ApJ,491,L107 Schneider D.P.,Knapp G.R.,Hawley S.L.,et al.,2002, AJ,123,458Scholz R.-D.,Irwin M.,Ibata R.,et al.,2000,A&A,353, 958Urban S.E.,Corbin T.E.,WycoﬀG.L.et al.,1998,AJ, 115,1212van Altena W.F.,Lee J.T.,Hoﬄeit E.D.,1995,The Gen-eral Catalogue of Trigonometric Stellar Parallaxes,Fourth Edition(Schenectady:L.Davis Press)This paper has been typeset from a T E X/L A T E Xﬁle prepared by the author.。

剑桥雅思真题9-阅读Test 1(附答案)

剑桥雅思真题9-阅读Test 1（附答案）Reading Passage 1You should spend about 20 minutes on QUESTIONS 1-13 which are based on Reading Passage 1 below.William Henry PerkinThe man who invented synthetic dyesWilliam Henry Perkin was born on March 12, 1838, in London, England. As a boy, Perkin's curiosity prompted early interests in the arts, sciences, photography, and engineering. But it was a chance stumbling upon a run-down, yet functional, laboratory in his late grandfather's home that solidified the young man's enthusiasm for chemistry.As a student at the City of London School, Perkin became immersed in the study of chemistry. His talent and devotion to the subject were perceived by his teacher, Thomas Hall, who encouraged him to attend a series of lectures given by the eminent scientist Michael Faraday at the Royal Institution. Those speeches fired the young chemist's enthusiasm further, and he later went on to attend the Royal College of Chemistry, which he succeeded in entering in 1853, at the age of 15.At the time of Perkin's enrolment, the Royal College of Chemistry was headed by the noted German chemist August Wilhelm Hofmann. Perkin's scientific gifts soon caught Hofmann's attention and within two years, he became Hofmann's youngest assistant. Not long after that, Perkin made the scientific breakthrough that would bring him both fame and fortune.At the time, quinine was the only viable medical treatment for malaria. The drug is derived from the bark of the cinchona tree, native to South America, and by 1856 demand for the drug was surpassing the available supply. Thus, when Hofmann made some passing comments about the desirability of a synthetic substitute for quinine, it was unsurprising that his star pupil was moved to take up the challenge.During his vacation in 1856, Perkin spent his time in the laboratory on the top floor of his family's house. He was attempting to manufacture quinine from aniline, an inexpensive and readily available coal tar waste product. Despite his best efforts, however, he did not end up with quinine. Instead, he produced a mysterious dark sludge. Luckily, Perkin's scientific training and nature prompted him to investigate the substance further. Incorporating potassium dichromate and alcohol into the aniline at various stages of the experimental process, he finally produced a deep purple solution. And, proving the truth of the famous scientist Louis Pasteur's words 'chance favours only theprepared mind’. Perkin saw the potential of his unexpected find.Historically, textile dyes were made from such natural sources as plants and animal excretions. Some of these, such as the glandular mucus of snails, were difficult to obtain and outrageously expensive. Indeed, the purple colour extracted from a snail was once so costly that in society at the time only the rich could afford it. Further, natural dyes tended to be muddy in hue and fade quickly. It was against this backdrop that Perkin's discovery was made.Perkin quickly grasped that his purple solution could be used to colour fabric, thus making it the world's first synthetic dye. Realising the importance of this breakthrough, he lost no time in patenting it. but perhaps the most fascinating of all Perkin's reactions to his find was his nearly instant recognition that the new dye had commercial possibilities.Perkin originally named his dye Tyrian Purple, but it later became commonly known as mauve (from the French for the plant used to make the colour violet). He asked advice of Scottish dye works owner Robert Pullar, who assured him that manufacturing the dye would be well worth it if the colour remained fast (i.e. would not fade) and the cost was relatively low. So, over the fierce objections of his mentor Hofmann, he left college to give birth to the modern chemical industry. With the help of his father and brother, Perkin set up a factory not far from London. Utilising the cheap and plentiful coal tar that was an almost unlimited byproduct of London's gas street lighting, the dye works began producing the world's first synthetically dyed material in 1857. The company received a commercial boost from the Empress Eugenie of France, when she decided the new colour flattered her. Very soon, mauve was the necessary shade for all the fashionable ladies in that country. Not to be outdone, England's Queen Victoria also appeared in public wearing a mauve gown, thus making it all the rage in England as well. The dye was bold and fast, and the public clamoured for more. Perkin went back to the drawing board.Although Perkin's fame was achieved and fortune assured by his first discovery, the chemist continued his research. Among other dyes he developed and introduced were aniline red (1859) and aniline black (1863) and, in the late 1860s, Perkin's green. It is important to note that Perkin's synthetic dye discoveries had outcomes far beyond the merely decorative. The dyes also became vital to medical research in many ways. For instance, they were used to slain previously invisible microbes and bacteria, allowing researchers to identify such bacilli as tuberculosis, cholera, and anthrax. Artificial dyes continue to play a crucial role today. And, in what would have been particularly pleasing to Perkin, their current use is in the search for a vaccine against malaria. Question 1-7Do the following statements agree with the information given in Reading Passage 1?In boxes 1-7 on your answer sheet, writeTRUE if the statement agrees with the informationFALSE if the statement contradicts the informationNOT GIVEN if there is no information on this1. Michael Faraday was the first person to recognise Perkin's ability as a student of chemistry.2. Michael Faraday suggested Perkin should enrol in the Royal College of Chemistry.3. Perkin employed August Wilhelm Hofmann as his assistant.4. Perkin was still young when he made the discovery that made him rich and famous.5. The trees from which quinine is derived grow only in South America.6. Perkin hoped to manufacture a drug from a coal tar waste product.7. Perkin was inspired by the discoveries of the famous scientist Louis Pasteur.Question 8-13Answer the questions below.Choose NO MORE THAN TWO WORDS from the passage for each answer.Write your answers in boxes 8-13 on your answer sheet.8 Before Perkin's discovery, with what group in society was the colour purple associated?9 What potential did Perkin immediately understand that his new dye had?10 What was the name finally used to refer to the first colour Perkin invented?11 What was the name of the person Perkin consulted before setting up his own dye works?12 In what country did Perkin's newly invented colour first become fashionable?13 According to the passage, which disease is now being targeted by researchers using synthetic dyes?Reading Passage 2You should spend about 20 minutes on QUESTIONS 14-26 which are based on Reading Passage 2 below.Is there anybody out there?The search for extra-terrestrial intelligencesThe question of whether we are alone in the Universe has haunted humanity for centuries, but we may now stand poised on the brink of the answer to that question, as we search for radio signals from other intelligent; civilisations. This search, often known by the acronym SETI (search for extra-terrestrial intelligence), is a difficult one. Although groups around the world have been searching intermittently for three decades, it is only now that we have reached the level of technology where we can make a determined attempt to search all nearby stars for any sign of life.A The primary reason for the search is basic curiosity -the same curiosity about the natural world that drives all pure science. We want to know whether we are alone in the Universe. We want to know whether life evolves naturally if given the right conditions, or whether there is something very special about the Earth to have fostered the variety of life forms that we see around us on the planet. The simple detection of a radio signal will be sufficient to answer this most basic of all questions. In this sense, SETI is another cog in the machinery of pure science which is continually pushing out the horizon of our knowledge. However, there are other reasons for being interested in whether life exists elsewhere. For example, we have had civilisation on Earth for perhaps only a few thousand years, and the threats of nuclear war and pollution over the last few decades have told us that our survival may be tenuous. Will we last another two thousand years or will we wipe ourselves out? Since the lifetime of a planet like ours is several billion years, we can expect that, if other civilisations do survive in our galaxy, their ages will range from zero to several billion years. Thus any other civilisation that we hear from is likely to be far older, on average, than ourselves. The mere existence of such a civilisation will tell us that long-term survival is possible, and gives us some cause for optimism. It is even possible that the older civilisation may pass on the benefits of their experience in dealing with threats to survival such as nuclear war and global pollution, and other threats that we haven't yet discovered.B In discussing whether we are alone, most SETI scientists adopt two ground rules. First, UFOs (Unidentified Flying Objects) are generally ignored since most scientists don’t consider the evidence for them to be strong enough to bear serious consideration (although it is also important to keep an open mind in case any really convincing evidence emerges in the future). Second, we make a very conservative assumption that we are looking for a life form that is pretty well like us, since if it differs radically from us we may well not recognise it as a life form, quite apart from whether we are able to communicate with it. In other words, the life form we are looking for may well have two green heads and seven fingers, but it will nevertheless resemble us in that it should communicate with its fellows, be interested in the Universe, live on a planet orbiting a star like our Sun. And perhaps most restrictively, have a chemistry, like us, based on carbon and water.C Even when we make these assumptions, our understanding of other life forms is still severely limited. We do not even know, for example, how many stars have planets, and we certain^ do not know how likely it is that life will arise naturally, given the right conditions. However, when we look at the 100 billion stars in our galaxy (the Milky Way), and 100 billion galaxies in the observable Universe, it seems inconceivable that at least one of these planets does not have a life form on it; in fact, the best educated guess we can make, using the little that we do know about the conditions for carbon-based life, leads us to estimate that perhaps one in 100,000 stars might have a life-bearing planet orbiting it. That means that our nearest neighbours are perhaps 100 light years away, which is almost next door in astronomical terms.D An alien civilisation could choose many different ways of sending information across the galaxy, but many of these either require too much energy, or else are severely attenuated while traversing the vast distances across the galaxy. It turns out that, for a given amount of transmitted power, radio waves in the frequency range 1000 to 3000 MHz travel the greatest distance, and so all searches to date have concentrated on looking for radio waves in this frequency range. So far there have been a number of searches by various groups around the world, including Australian searches using the radio telescope at Parkes, New South Wales. Until now there have not been any detections from the few hundred stars which have been searched. The scale of the searches has been increased dramatically since 1992, when the US Congress voted NASA $10 million per year for ten years to conduct a thorough search for extra-terrestrial life. Much of the money in this project is being spent on developing the special hardware needed to search many frequencies at once. The project has two parts. One part is a targeted search using the world's largest radio telescopes, the American-operated telescope in Arecibo, Puerto Rico and the French telescope in Nancy in France. This part of the project is searching the nearest 1000 likely stars with high sensitivity for signals in the frequency range 1000 to 3000 MHz. The other part of the project is an undirected search which is monitoring all of space with a lower sensitivity, using the smaller antennas of NASA's Deep Space Network.E There is considerable debate over how we should react if we detect a signal from an alien civilisation. Everybody agrees that we should not reply immediately. Quite apart from the impracticality of sending a reply over such large distances at short notice, it raises a host of ethical questions that would have to be addressed by the global community before any reply could be sent. Would the human race face the culture shock if faced with 8 superior and much older civilisation? Luckily, there is no urgency about this. The stars being searched are hundreds of light years away, so it takes hundreds of years for their signal to reach us, and a further few hundred years for our reply to reach them. It's not important, then, if there's a delay of a few years, or decades, while the human race debates the question of whether to reply, and perhaps carefully drafts a reply. Question 14-17Reading Passage 2 has five paragraphs, A-E.Choose the correct heading for paragraphs B-E from the list of headings below.Write the correct number, i-vii, in boxes 14-17 on your answer sheet.15 Paragraph C16 Paragraph D17 Paragraph EQuestion 18-20Answer the questions below.Choose NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage for each answer.Write your answers in boxes 18-20 on your answer sheet.18What is the life expectancy of Earth?19What kind of signals from other intelligent civilisations are SETI scientists searching for?20How many stars are the world's most powerful radio telescopes searching?Question 21-26Do the following statements agree with the views of the writer in Reading Passage 2?In boxes 21-26 on your answer sheet, writeYES if the statement agrees with the views of the writerNO if the statement contradicts the views of the writerNOT GIVEN if it is impossible to say what the writer thinks about this21. Alien civilisations may be able to help the human race to overcome serious problems.22. SETI scientists are trying to find a life form that resembles humans in many ways.23. The Americans and Australians have co-operated on joint research projects.24. So far SETI scientists have picked up radio signals from several stars.25. The NASA project attracted criticism from some members of Congress.26. If a signal from outer space is received, it will be important to respond promptly.Reading Passage 3You should spend about 20 minutes on QUESTIONS 27-40 which are based on Reading Passage 3 below.The history of the tortoiseIf you go back far enough, everything lived in the sea. At various points in evolutionary history, enterprising individuals within many different animal groups moved out onto the land, sometimes even to the most parched deserts, taking their own private seawater with them in blood andcellular fluids. In addition to the reptiles, birds, mammals and insects which we see all around us, other groups that have succeeded out of water include scorpions, snails, crustaceans such as woodlice and land crabs, millipedes and centipedes, spiders and various worms. And we mustn’t forget the plants, without whose prior invasion of the land none of the other migrations could have happened.Moving from water to land involved a major redesign of every aspect of life, including breathing and reproduction. Nevertheless, a good number of thorough going land animals later turned around, abandoned their hard-earned terrestrial re-tooling, and returned to the water again. Seals have only gone part way back. They show us what the intermediates might have been like, on the way to extreme cases such as whales and dugongs. Whales (including the small whales we call dolphins) and dugongs, with their close cousins the manatees, ceased to be land creatures altogether and reverted to the full marine habits of their remote ancestors. They don't even come ashore to breed. They do, however, still breathe air, having never developed anything equivalent to the gills of their earlier marine incarnation. Turtles went back to the sea a very long time ago and, like all vertebrate returnees to the water, they breathe air. However, they are, in one respect, less fully given back to the water than whales or dugongs, for turtles still lay their eggs on beaches. There is evidence that all modern turtles are descended from a terrestrial ancestor which lived before most of the dinosaurs. There are two key fossils called Proganochelys quenstedti and Paiaeockersis talampayensis dating from early dinosaur times, which appear to be close to the ancestry of all modern turtles and tortoises. You might wonder how we can tell whether fossil animals lived on land or in water, especially if only fragments are found. Sometimes it's obvious. Ichthyosaurs were reptilian contemporaries of the dinosaurs, with fins and streamlined bodies. The fossils look like dolphins and they surely lived like dolphins, in the water. With turtles it is a little obvious. One way to tell is by measuring the bones of their forelimbs.Walter Joyce and Jacques Gauthier, at Yale University, obtained three measurements in these particular bones of 71 species of living turtles and tortoises. They used a kind of triangular graph paper to plot the three measurements against one another. All the land tortoise species formed a tight cluster of points in the upper part of the triangle; all the water turtles cluster in the lower part of the triangular graph. There was no overlap, except when they added some species that spend time both in water and on land. Sure enough, these amphibious species show up on the triangular graph approximately half way between the 'wet cluster’ of sea turtle and the 'dry cluster* of land tortoises. The next step was to determine where the fossils fell. The bones of P. quenstedti and P.talampayensis leave us in no doubt their points on the graph are right in the thick of the dry cluster. Both these fossils were dry-land tortoises. They come from the era before our turtles returned to the water.You might think, therefore, that modem land tortoises have probably stayed on land ever since those early terrestrial times, as most mammals did after a few of them went back to the sea. But apparently not. If you draw out the family tree of all modem turtles and tortoises, nearly all the branches are aquatic. Today's land tortoises constitute a single branch, deeply nested among branches consisting of aquatic turtles. This suggests that modem land tortoises have not stayed on land continuously since the time of P. quenstedti and P. talampayensis. Rather, their ancestors were among those who went back to the water, and they then re-emerged back onto the land in (relatively) more recent times.Tortoises therefore represent a remarkable double return. In common with all mammals, reptilesand birds, their remote ancestors were marine fish and before that various more or less worm-like creatures stretching back, still in the sea, to the primeval bacteria. Later ancestors lived on land and stayed there for a very large number of generations. Later ancestors still evolved back into the water and became sea turtles. And finally they returned yet again to the land as tortoises, some of which now live in the driest of deserts.Question 27-30Answer the questions below.Choose NO MORE THAN TWO WORDS from the passage for each answer.Write your answers in boxes 27-30 on your answer sheet.27What had to transfer from sea to land before any animals could migrate?28Which TWO processes are mentioned as those in which animals had to make big changes as they moved onto land?29Which physical feature, possessed by their ancestors, do whales lack?30Which animals might ichthyosaurs have resembled?Question 31-33Do the following statements agree with the information given in Reading Passage 3?In boxes 31-33 on your answer sheet, writeTRUE if the statement agrees with the informationFALSE if the statement contradicts the informationNOT GIVEN if there is no information on this31. Turtles were among the first group of animals to migrate back to the sea.32. It is always difficult to determine where an animal lived when its fossilised remains are incomplete.33. The habitat of ichthyosaurs can be determined by the appearance of their fossilised remains. Question 34-39Complete the flow-chart below.Choose NO MORE THAN TWO WORDS AND/OR A NUMBER from the passage for each answer.Write your answers in boxes 34-39 on your answer sheet.Method of determining where the ancestors of turtles and tortoises come fromQuestion 40Choose the correct letter, A, B, C or D.Write the correct letter in box 40 on your answer sheet.40. According to the writer, the most significant thing about tortoises is thatA. they are able to adapt to life in extremely dry environments.B. their original life form was a kind of primeval bacteria.C. they have so much in common with sea turtles.D. they have made the transition from sea to land more than once.参考答案1 FALSE2 NOT GIVEN3 FALSE4 TRUE5 NOT GIVEN6 TRUE7 NOT GIVEN8 (the / only) rich9 commercial (possibilities)10 mauve (was/is)11 (Robert) Pullar12 (in) France13 malaria (is)14 iv15 vii16 i17 ii18 several billion years19 radio (waves/signals)20 1000(stars)21 YES22 YES23 NOT GIVEN24 NO25 NOT GIVEN26 NO27 plants28 (IN EITHER ORDER; BOTH REQUIRED FOR ONE MARK) breathing; reproduction29 gills30 dolphins31 NOT GIVEN32 FALSE33 TRUE34 3 measurements35 (triangular) graph36 cluster37 amphibious38 half way39 dry-land tortoises40 D。

2023-2024学年内蒙古包头市青山区重点中学中考二模英语试题含答案

2023-2024学年内蒙古包头市青山区重点中学中考二模英语试题含答案注意事项1．考试结束后，请将本试卷和答题卡一并交回．2．答题前，请务必将自己的姓名、准考证号用0．5毫米黑色墨水的签字笔填写在试卷及答题卡的规定位置．3．请认真核对监考员在答题卡上所粘贴的条形码上的姓名、准考证号与本人是否相符．4．作答选择题，必须用2B铅笔将答题卡上对应选项的方框涂满、涂黑；如需改动，请用橡皮擦干净后，再选涂其他答案．作答非选择题，必须用05毫米黑色墨水的签字笔在答题卡上的指定位置作答，在其他位置作答一律无效．5．如需作图，须用2B铅笔绘、写清楚，线条、符号等须加黑、加粗．Ⅰ. 单项选择1、—In the coning three years, our country will _______ emergency food aid for Developing countries along the Belt and Road.A．afford B．offer C．provide D．support2、—We’ll study in different schools next term. I hope you’ll enjoy your time in the new school!— _______A．I’ll take your advice.B．The same to you． C．Congratulations! D．Me, too.3、一It shouldn't take long to clear up after the party if we all volunteer to help.一That's right. .A．The early bird catches the worm B．Put all your eggs in one basketC．Many hands make light work D．Actions speak louder than words4、---The CCTV March 15th Evening Party showed that the snack ‘spicy strip’ which children like eating is poisonous. --- Yes. Something __________ be done to make producers pay attention to food safety.A．need B．ought C．may D．must5、“Lichun” falls ______ February 4th this year. It is the beginning of spring and the first of the 24 solar terms of the Chinese lunar calendar.A．at B．in C．on D．of6、— It's wonderful that Lily has been invited to the welcome party too!一I'm afraid she not come. She has been busy with her study recently.A．need B．must C．may D．should7、—What? We can take buses with just a mobile?—Yes. Buses in Yangzhou began to _____ Alipay app.A．share B．save C．search D．support8、---Shall we go on Friday or Saturday? ---Each is OK. It makes no______ to me.A．choice B．change C．difference D．decision9、---Mum, can I throw away the old clock? We it for many years.---No, you can’t. It still works well and remember saving is getting.A．have bought B．have had C．bought10、——I'm really _______ when I speak English in class.——Take it easy. You're the best.A．nervous B．surprised C．comfortable D．confidentⅡ. 完形填空11、Once I thought love meant flowers, gifts and sweet kisses. So, I really not sure whether there was love between my parents. They didn’t act in the romantic ways that I read in books or I saw on TV, and it was 1 for them to send flowers to each other on Vale ntine’s Day(情人节).One day, my mother was sewing(缝) a quilt. I 2 her if there was love between them. She stopped her work and looked up. I had never asked her such a question before, so her eyes were full of 3 . After thinking for a few minutes, she said, “Look at this thread (线). Sometimes it 4 , but most of the time it disappears in the quilt. If life is a quilt, then love 5 a thread. Y ou can 6 see the thread anywhere or anytime, but it’s really there, and makes the quilt long and strong.” I listened carefully but I couldn’t understand her 7 the next spring.My mother suddenly got seriously ill. Every morning and dusk (黄昏) after she went back from the hospital, my father helped my mother walk slowly on the country road. There were many beautiful flowers, green grass and trees, and the sunshine gently fell on them 8 the leaves.All of these made up the most beautiful picture in the world. Reading their eyes, I knew they loved each other and they 9 stay by each o ther’ s side when necessary.Love was just a thread in the quilt of our life. Love is 10 , making life strong and warm.1．A．possible B．impossible C．successful2．A．asked B．told C．said3．A．surprises B．sadness C．anger4．A．appears B．grows C．mixes5．A．is different from B．is similar to C．is far from6．A．hardly B．usually C．always7．A．after B．in C．until8．A．across B．through C．under9．A．were ready to B．happened to C．were up to10．A．inside B．outside C．besideⅢ. 语法填空12、二、语法填空：用所给单词的适当形式填空，未给词的限填一词。

2015上海市徐汇区九年级英语二模试题word版(纯手工)

2015上海市徐汇区九年级英语二模试题（纯手工）1.Little Tom hid himself under the bed.Which of the following is correct for the underlined word?A /haid/B /ha：d/ C/ hІd/ D/hᵆd/2.Which of the following underlined parts is different in pronunciation from others?A I still need a couple of days to fix it.B He has never been to foreign country before.C Could you please speak louder, please?D Don’t touch that ancient painting.3.I received _____ invitation to Alex and Kelly’s wedding party on the night of May 20th.A theB /C aD an4.There are too many ______of fantastic hotels online.It’s really hard to decide.A newsB choicesC politiesD manners5.You can tell from the posters and photos _____the wall that Chen is a big fan of Jay Chou.A inB betweenC onD above6.As ______first English teacher,Ms White has a great influence on the children.A theyB themC theirD theirs7._____wants to make friends with people who are rude to others.A NobodyB Somebody ＣAnybody D Everybody8.He rushed into classroom when Mr.Simpson______about American history.A talkedB had talkedC would talkD was talking9.In the talent show,I performed well and Ann did even ____.A goodB wellC betterD best10.We have decided to keep the secret just among us,___we will not tell it to anyone else.Abut B so C for D or11.A:_______don’t you attend any clubs after school?B:Because I am slow at doing my homework.I need more time tahn you do.A WhereB WhyC whyD When12.People in China all wonder when we _____ worry about we breathe.A can’tB needn’tC shouldn’tD mustn’t13.How about ______ to English radio programs every day if you want to improve your listening skill?A listenB to listenC listenedD listening14.All the passengers will stay at the airport for another day if the snow storm______tomorrow.A doesn’t stopB didn’t stop Ｃwon’t stop D hasn’t stop15.People never know how important health is ____they lose it.A ifB untilC althoughD after16.A few days ago a policeman died on duty and many citizens _____flowers to the place where he lost his life voluntarily.A sendB had sentC sentD were sending17.Let’s sit down and have a look at your design,______?A can’t youB will youC shall weD don’t we18.The free wi-fi service in the restaurant enables the customers ____the meal and fun of going online at the same time.A enjoyB to enjoyC enjoyingD enjoyed19.A:How do you like the film Paddington Brown?B:_______A Yes,I like it BＩthink so.C It’s so funny.D I don’t feel very well.20.A:Kevin didn’t manage to get a ticket for the football game.B:_______A Me too.B What a pity!C I am glad to hear it.D That sounds great!Complete the following passage with the words in the box.Each can only be used once.A.details B yearly C around D abroad D locationsA murder will take place this weekend in the peaceful seaside town ofLangley,Washington. In fact, a murder has occurred there every February for the past 25 years. But don’t panic! It’s all part of the town’s___21__ Mystery Weekend.The event began as a local event in 1984 and now attracts visitors from over the U.S. and even___22__ . Would-be detectives arrive and check in at the visitor center on Saturday. There, they receive a packet, including a newspaper with ___23__ about the crime and information telling where to find clues. Participants then travel to various shops, restaurants and other__24_____, picking up clues as they go. Along the way, they encounter and interview suspects played by local townspeople. Most Langley residents participate in some way in the Mystery Weekend, a true community event.A for exampleB openC resultsD above allE drivingAmateur(业余的）detectives should turn in their ___25____ at 4:00 p.m on Sunday. Then as everyone gathers, the murderer is found and arrested, and prizes are awarded for correct answers. It’s the perfect ending for a murder mystery and enormous fun for those who get to play detectives.For visitors, Mystery Weekend is not only fun but also a great introduction to the beauty of Langley. It’s a very attractive community with historic buildings, exciting ocean views and ___26____, friendlypeople. Since Langley is on an island, a fun way to get there is by taking a car ferry to the nearby town of Clinton and then _____27_ the rest of the way. Langley has a delightful selection of inns(小旅店）with bed and breakfasts that are_______28 all year round. And activities in Langley aren’t limited to Mystery Weekend. There is also great hiking, biking, golfing and diving to enjoy. And for a special adventure, visitors can book on one of the whale – watching ships that leave nearby harbors each day. Complete the sentences with the given words in their proper forms.29.Recently many interesting children’s _____have been on shown in the cinemas.(film)That mother is very patient and always talks _____to her child.(gentle) 30.These pills are supposed to take only ____a day.More than that isn’t helpful.(second)Please help ______ to some fruits and drinks on the table,Annie.(you) 31.There is truth in an old saying that ______comes with age.(wise)The roller coaster(过山车）seems so _______.I am not brave enough to take the ride.(frighten)32.I am sure she failed in the competition because of the _____look on her face.(happy)33.It is impossible _____that the historical problem in such a short time.(solution)Complete the following sentences as required.34.The teachers of No.1Middle School have a meeting at 3o’clock Friday afternoon.(改为否定句）The teachers of No.1Middle School_______ _____ a meeting at 3o’clock Friday afternoon.35.The cute Baymax from the Big Hero 6 attracted people of different ages to this cartoon film.(改为被动语态）People of different ages _____ _____ by the cute Baymax from the Big Hero 6 to this cartoon film.anic（有机的)vegetables cost much more than non-organic vegetables.(保持句意基本不变）Non-organic v egetables don’t cost _____ ____as organic vegetables. 37.He feels so proud to be elected chairman of the Students’Union!(感叹句）_____ _____ he feels to be elected chairman of the Students’Union!38.In some areas bamboos,instead of wood ,are used to make furniture.(保持句意基本不变)In some areas furniture is _____ ______ bamboos instead of wood.39.Will Emma Arrive in Shanghai in two days?He kept asking me.(合并为一句）He kept asking me ______ Emma _____arrive in Shanghai in two days.40.by himself, enough, find out,he,t o clever,isn’t,the truth______________________________________________________Reading comprehensionA Choose the best answerEvery country in the world has a flag.A flag is a piece of cloth with a picture or pattern on it.The flag is a symbol that stands for the country.It is a custom in many places for people to fly hang a flag.The flag tells something about the country and its culture.This maybe about its land,its history,or the things that people do there.Many flags have patterns of stripes(条纹).The flag of Italy has a green stripe,a white stripe and a red stripe.Each stripe tells something about Italy.The white stripe is a symbol of Italy’s snowy mountains.Some flags show pictures.The flag of Canada has a picture of red maple(枫树) leaf.Which is a symbol of the maple trees in Canada.The Mexican flag has both pattern of stripes and a picture.The picture shows an eagle eating a snake. This picture comes from a very old Mexican story.A flag may also tell a country’s past.The American flag is called the St ars and Stripes.It has a pattern of fifty stars and thirteen stripes.The fifty stars are a symbol of the fifty states in the country,and the thirteen stripes are a symbol of the country’s first thirteen colonies(殖民地).However, a flag may be a symbol of a group,a school,or an event like the Olympics.The flag of the Olympics shows five rings of different colours that connect.Each flag is a symbol for a part of the world of the world of the joins in the Olympics.The Red Cross is a group that helps people who are in trouble.If a person sees a the Red Cross flag,which has a red cross against a white background,he knows he can ask for help.People may fly a flag as a custom on a holiday,Children’s Day in Japan is a holiday when the country wishes for children’s h appiness.It is a custom on this day to fly a flag with a picture of fish.Flags are also used as a way to talk.A flag with patterns can be very helpful to people who do not speak the same language.Sailors on ships use flags to talk to sailors on other ships.They may not speak the same language,but they know what the patterns mean.A flag with blue and white squares says＂no.＂A flag with five stripes that are blue,white and red says ＂yes．＂41.We can usually see_____on a flag.A different languageB a country’s pastC a picture or patternD people42Which of the following is the flag of Mexico?43.We can tell from the American flag that there are ____states in thecountry.A1 B 3 C 13 D 5044.A flag with a red cross against a white background means＂＿＿＿＿.＂A There is a church here.B The shop is closedC You must stop immediatelyD We offer people help they need45.Sailors on ships use flags to talk because _______A flying or hanging a flag is a custom on ships.B patterns are the ＂language＂sailors all understand.C flags can be seen easily from a faraway distance.D it’s considered polite for sailors to talk with flags46.The best title for the passage is _____A The Facts of FlagsB The History of FlagsC The Development of FlagsD The Secrets of FlagsChoose the words or expressions and complete the passageI used to watch her from my kitchen window.She seemed so _____47as she made her way through the crowd of boys on the playground.The school was across the street from our home and I would often watch the kids as they played during the break. I remember the first day I saw her playing basketball.I watched in wonder as she ran circles around he other kids.She managed to shoot jump shots just over their heads and into the net.The boys always tried to stop her but no one could.I began to noticeher at other times, basketball in hand,playing alone.One day I asked her why she practiced so much.She said immediately.＂I want to go college.The only way I can go is to get a scholarship(奖学金）I am going to play college basketball. I want to be the best. My daddy tells me____48_the dream is big enough, the facts don't count. "Well, I had to give it to her-She was determined. I watched her through those junior high years and into high school.Every week, she led her school team to _______49.One day in her senior year, I saw her sitting in the grass, head in her arms.I walked across the street and sat down in the cool grass beside her. ________50 I asked what was wrong. "I am just not tall enough ,"came a soft reply. The coach told her that at 5'5" she would probably never get to play for a top ranked team-much less offered a scholarship. So she should stop ______51_ college. I could feel her disappointment, I asked her if she had talked to her dad about it yet. She told me that her father said those coaches were wrong. They just did not understand the power of a dream. He told her that if she truly wanted a scholarship and that nothingcould stop her except one thing-her own _______52.The next year, as she and her team went to the Northern California Championship game, she was offered a scholarship and on the college team. She was going to get the college education that she had lookedforward to.47.A beautiful B crazy C small D responsible48.A if B although C because D unless49.A sports B victory C rest D future50.A Luckily B Suddenly C Quietly D Usually51.A worrying about B dreaming about C looking for D depending on52.A attitude B family C height D skillRead the passage and fill in the blanks with proper words.It is a great but difficult project to set up a permanent(永久的）human settlement on Mars.Over 200,000volunteers from more than 120 countries have applied to take a one-way trip to Mars.The project, run by a Dutch company named Mars One,aims to send a group of volunteers to Mars,and because of the physiological(生理上的）change in the human body after a stay on Mars,there’d be no chance ofc_______back.So it’s only a one-way trip!However,that hasn’t stopped volunteers becoming one of Mars’ first citizens.＂This is turning out to be the most welcome job in the history.＂says Bas Lansdorp,co-founder of Mars One.Day-to-day life on Mars will be not easy.The daily work willi_____building greenhouses or doing some research--all in a lonely environment.Mars is not f_____ to life.Its atmosphere is so thin that it won’t protect you from harmful radiation(辐射）from the sun.You can’t breathe the air and it is very cold on Mars,with an average temperature of around-50°C.There is no running water on the surface of Mars.The is frozen or hidden u______.But Mars One says the project is not looking for volunteers with some skill such as a science degree.I_______,they are looking for people who have “a deep sense of purpose and responsibility”.As the first group of people living on Mars,volunteers should be “willing to build and keep a healthy r_____with the Earth”.They also want volunteers who are “curious,creative and good at finding ways of dealing with all kinds of problems”.The volunteers will receive at least eight years training b_____ they leave Earth,the company says.The first group of 24 volunteers is set to fly to Mars in 2024.Answer the questionsA nine-year-old boy with a keen eye for both fashion and business is taking the bakery world by storm.Cory Nieves, from New Jersey, who uses the business name 'Mr Cory', not only wears tailored(定制的）suits and silk ties from trendy grown-up stores, but he's also the CEO of his very own cookie（饼干）company called Mr Cory's Cookies.On his website, which has an impressive 3,000 followers, Cory shows his perfect fashion sense.In one photo, he stands in front of his cookie stand in white shorts, a dark jacket ,wearing fashionable glasses and a stack of bracelets to look more attractive.Cory wrote on his website that he first came up with the idea to start a business when he and his mother moved to New Jersey from New York City in 2009, and he decided to help mom buy a car.Then he began selling hot cocoa drinks in front of his home and finally he has developed into the cookie business.Not only has he developed a fan base for his scrumptious desserts, but he has also won over followers who like his fashion sense.In the comment section on his page,fans have expressed their love,with one person writing “this kid is very smart.”The project may have begun as a way to buy his mom a car,but Cory says h e now has even higher hopes,”I am going to do it to earn money for college and learning how to run a business,”he told North . Besides being CEO of the cookie company, Cory is also an actor and model.What’s the name of Cory Nieve’s coolie company?How many people show interest in Cory on his website page?_____________________________________________________Why did Cory have the idea to start a business after he moved to New Jersey?______________________________________________________ What actually helps Cory win over so many fans,his delicious cookies or his fashion sense?________________________________________________________ How is Cory probably going to use the money he earns?_____________________________________________________What kind of boy do you think Cory is after reading the passage?And why do you have that impression?I think______________________________________________ WritingsWrite a passage in at least 60words on the topic “I want to say to myself_______”.(以“我想对自己说‘_______’为题写一篇不少于60个字的短文，标点符号不占格）（注意：短文中不得出现任何人名，校名及其它相关信息，否则不予评分。

北京市海淀区九年级上学期期中考试英语试题及答案

北京市海淀区九年级上学期期中考试英语试题及答案一、听对话，从下面各题所给的A、B、C三幅图片选项与对话内容相符的图片。

每段对话你将听两遍。

（共4分，每小题1分）二、听对话或独白，根据对话或独白的内容，从下面各题所给的A、B、C三个选项中选择最佳选项。

每段对话或独白你将听两遍。

（共12分，每小题1分）5. What’s in the backpack?A. A notebook.B. A pencil box.C. A hair hand6. Whose backpack could it be?A. Jack’sB. Lily’sC. Maria’s请听一段对话，完成第7至8小题。

7. What is John doing now?A. Watching TV.B. Doing homework.C. Playing baseball.8. What does John hate?A. The shows.B. The rulesC. The games.请听一段对话，完成第9至10小题。

9.How long will the holiday be?A. Two days.B. Three days.C. Four days.10. What is Tina going to do during the holiday?A. Go hiking and camping.B. Go to the beach.C. Visit the museum.请听一段对话，完成第11至13小题。

11. When is the party?A. Next Sunday evening.B. Next Saturday evening.C. Next Friday evening.12. What will the boy probably wear for the party?A. A shirt and tie.B. A suit and shirt.C. A suit and tie.13. What can we know about the boy?A. He has no friends.B. He needs more time.C. He wants some advice.请听一段对话，完成第14至16小题。

寻找地球以外生命的意义英语作文

寻找地球以外生命的意义英语作文The Search for Extraterrestrial Life: Its Significance and Impact.Since the dawn of civilization, humanity has looked towards the heavens with a sense of curiosity and awe. The vast expanse of the universe, filled with millions of stars and galaxies, has always fascinated us. One of the most compelling questions that has persisted throughout the ages is whether we are alone in this vast cosmos or if there is other life beyond Earth. The search for extraterrestrial life has been a driving force in science and technology, pushing the boundaries of our understanding and sparking imaginations.The significance of searching for extraterrestrial life lies in multiple dimensions. Firstly, it challenges our fundamental understanding of the universe. If life exists beyond Earth, it would suggest that the universe is teeming with life, potentially millions or even billions ofcivilizations. This would revolutionize our understanding of the universe, making it less of a lonely and desolate place and more of a vibrant and diverse ecosystem.Secondly, the search for extraterrestrial life has the potential to answer fundamental questions about our own existence. Studying life beyond Earth could provideinsights into the origin and evolution of life, potentially giving us a better understanding of our own biological and cultural development. It could also provide clues about the potential for life to exist in other environments, such as on other planets or in extreme conditions here on Earth.Moreover, the search for extraterrestrial life is a powerful driving force for scientific innovation and technological advancement. It has spurred the development of new telescopes, probes, and spacecraft, enabling us to explore deeper into the universe than ever before. The technologies developed for this purpose have also found applications in other fields, such as medicine, communication, and even everyday life.The impact of the search for extraterrestrial life is also profound. It has fostered a sense of unity and cooperation among people from different cultures and backgrounds. The shared goal of finding life beyond Earth has transcended political and ideological divides, bringing people together in a common cause. This spirit of cooperation and exploration has the potential to bringabout positive changes in society, promoting understanding and respect among diverse groups.Additionally, the discovery of extraterrestrial life could have profound philosophical and religious implications. It could challenge our understanding of our place in the universe and our purpose as human beings. It could also lead to new discussions and debates about the nature of life, consciousness, and the meaning of existence.In conclusion, the search for extraterrestrial life is not just a scientific quest but a journey that has the potential to transform our understanding of the universeand ourselves. It challenges our fundamental beliefs and pushes the boundaries of our imagination. The discovery ofextraterrestrial life, whether it be microbial organisms or intelligent civilizations, would be a momentous occasion in human history, marking a new era of exploration and discovery. As we continue to search the heavens for signs of life, we also search for answers to the ultimate questions about our own existence and the vastness of the universe.。

高三英语苏教版试卷

高三英语苏教版试卷考试范围：xxx；考试时间：xxx分钟；出题人：xxx姓名：___________班级：___________考号：___________1．答题前填写好自己的姓名、班级、考号等信息2．请将答案正确填写在答题卡上一、单项选择1.The weather ________ be very cold at times, though it’s usually warm in spring in my home-town. A．can B．may C．must D．will2.– I wonder how much you charge for your services.-- The first two are free ____ the third costs $30.A．while B．until C．when D．before3.Whoever does not have a mobile phone must borrow _____ because you will certainly need ____ for the tour.A．one; it B．it; one C．it; it D．that; this4. ________ your poor record in school, we think you should study harder.A．In charge ofB．In case ofC．In spite ofD．In view of5.—Do you think he is the only person for the job?—I’m not quite sure but he’ll prove_______ to the task.A．equalB．essentialC．specialD．superior6.Between the two parts of the concert is an interval, ___ the audience can buy ice-creams. A．whenB．whereC．thatD．which7.I hope we’ve got it takes to make our love last—if anything is real, the heart will make it plain. Athat Bwhat Cwhen Dwhether8.—Is Paul playing basketball for his school?—Well,he ,But he has given it up and switched to playing volleyball.A．is B．was C．has D．had9.24. More than one ________ the people heart and soul.A．officials have servedB．official has served forC．official has servedD．official have served for10.______ to train his daughter in English, he put an ad like this in the paper, “______, an English teacher for a ten-year-old girl.”A．Determined; WantedB．Determined; WantingC．Determine; WantedD．Determining; Wanting评卷人得分二、完形填空完型填空(共20小题;每小题1.5分, 满分30分)阅读下面短文，从短文后各题所给的四个选项(A、B、C、D)中，选出可以填入空白处的最佳选项，并在机读卡上将该选项涂黑。

2023届上海市虹口区高三下学期二模英语试题

2023届上海市虹口区高三下学期二模英语试题一、短对话1．A．Boring. B．Special.C．Delicious . D．Traditional.2．A．£12. B．£24. C．£6. D．£8.4.3．A．He didn’t work last week.B．He managed to avoid being fined. C．He was fined. D．He is always a careful bike rider.4．A．It took the man a long time to arrive.B．The traffic was not busy that morning.C．A traffic accident happened on the man’s way here.D．The man needn’t go to work on Monday morning.5．A．She makes efforts to organize the party. B．She is going to be late for the party. C．She designs the dress with care. D．She is eager to attend the party.6．A．The concert is very popular.B．The woman has to finish her work first.C．The woman shouldn’t go to the concert.D．He doesn’t believe the woman has the concert ticket.7．A．The battery needs charging. B．It is nowhere to be found.C．The battery is positioned incorrectly. D．It is the wrong remote control.8．A．His project had to be suspended. B．His project was successful.C．He failed to get enough land for his project. D．He was unable to get enough funding. 9．A．He has little passion for English lessons. B．He has made great progress in English. C．He is uninterested in English songs. D．He is a major of music.10．A．Mr. Long’s briefing was unnecessarily lengthy.B．Mr. Long’s briefing was not relevant to the mission.C．The woman should have been more attentive.D．The woman needn’t have attended the briefing.二、短文听下面一段独白，回答以下小题。

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a r X i v :a s t r o -p h /0106222v 1 13 J u n 2001Astronomy &Astrophysics manuscript no.(will be inserted by hand later)Search for nearby stars among proper motion stars selected byoptical-to-infrared photometryI.Discovery of LHS 2090at spectroscopic distance of d ∼6pcR.-D.Scholz 1,H.Meusinger 2,⋆,and H.Jahreiß31Astrophysikalisches Institut Potsdam,An der Sternwarte 16,D–14482Potsdam,Germany e-mail:rdscholz@aip.de 2Th¨u ringer Landessternwarte Tautenburg,D–07778Tautenburg,Germany e-mail:meus@obelix.tls-tautenburg.de 3Astronomisches Rechen-Institut,M¨o nchhofstraße 12-14,D–69120Heidelberg,Germany e-mail:hartmut@ari.uni-heidelberg.deReceived ;acceptedAbstract.We present the discovery of a previously unknown very nearby star -LHS 2090at a distance of only d =6pc.In order to ﬁnd nearby (i.e.d <25pc)red dwarfs,we re-identiﬁed high proper motion stars (µ>0.18arcsec/yr)from the NLTT catalogue (Luyten 1979-1980)in optical Digitized Sky Survey data for two diﬀerent epochs and in the 2MASS data base.Only proper motion stars with large R −K s colour index and with relatively bright infrared magnitudes (K s <10)were selected for follow-up spectroscopy.The low-resolution spectrum of LHS 2090and its large proper motion (0.79arcsec/yr)classify this star as an M6.5dwarf.The resulting spectroscopic distance estimate from comparing the infrared JHK s magnitudes of LHS 2090with absolute magnitudes of M6.5dwarfs is 6.0±1.1pc assuming an uncertainty in absolute magnitude of ±0.4mag.Key words.astrometry and celestial mechanics:astrometry –astronomical data base:surveys –stars:late-type –stars:low mass,brown dwarfs1.IntroductionOur knowledge on the stellar content of the solar neigh-bourhood is still very incomplete.From the statistics of the Catalogue of Nearby Stars one can infer that at 10pc about 30%of all stars are so far undetected (Henry et al.1997).But the detailed observation of the very nearby stars is one of the main starting points for in-vestigations of the stellar luminosity function,the initial mass function as well as for the search for planetary sys-tems.Future missions for the detection of extrasolar plan-ets (SIM,TPF,DARWIN)will concentrate on very nearby stars (d <10pc)in order to be able to reveal not only Jupiter-class but also Earth-like planets.High proper motion catalogues, e.g.the Luyten Half Second (LHS)catalogue (Luyten 1979)and the New Luyten Two Tenths (NLTT)catalogue (Luyten 1979-1980)contain most of the known nearby stars (d <2R.-D.Scholz et al.:Search for nearby stars among proper motion stars.I.Discovery of LHS2090at d∼6pcSchmidt plates constitute theﬁrst epoch of Luyten’s high proper motion star surveys(e.g.Luyten1979). Nevertheless,few faint high proper motion stars can be found from second epoch POSS observations(Monet et al. 2000).South ofδ=−30◦,which is the POSS survey limit in the southern sky,only recently deep high proper motion surveys have been started using Schmidt plates(Scholz et al.2000;Ruiz et al.2001).New high proper motion stars as bright as the active M5star APMPM J0237-5928 (R=13.4,spectroscopic distance:12pc)discovered by Scholz et al.(1999)can be found in that region.There are several attempts to detect nearby stars ne-glecting the proper motion information during theﬁrst steps of the search.One possibility is to search for ex-tremely red faint objects,i.e.very late-type M dwarfs and the new class of L dwarfs obtained in the Two Micron All Sky Survey(2MASS)(Reid et al.2000;Gizis et al.2000) and in the DEep Near-Infrared Survey(DENIS)(Delfosse et al.2001).Another way to detect missing nearby M dwarfs consists in the subsequent observation of X-ray sources in order to identify young M dwarfs with small space motions not present in proper motion catalogues (Fleming1998).But all new nearby stars found in these surveys turned out to be high proper motion stars,at least in those cases when distances of less than about15pc were measured.As a logical consequence,we have started a search for the missing stars in the solar neighbourhood by combining the proper motion catalogues with near-infrared and op-tical sky surveys.The2MASS data base(2nd incremental release public data base)and the A2.0catalogue(Monet et al.1998)can well be used for that purpose.The proper motion stars,however,have to be re-identiﬁed in digitized sky survey(DSS)images at two diﬀerent epochs.bining proper motion and photometry Samples of very red(optical-to-infrared colour)point sources in the2MASS or DENIS survey may contain com-pact extragalactic sources,distant red giants,nearby red dwarfs and very nearby asteroids.If the source is relatively faint in the optical(R>10)and shows a proper motion of the order of0.1to10arcsec/yr(with Barnards’s star still being the record holder in stellar proper motions),it must be a dwarf.For a red giant with that faint apparent magnitude,the proper motion would transform to a very large space velocity(>1000km/s),which is much larger than the Galactic escape speed(cf.Leonard&Tremaine 1990;Meillon et al.1997).In a previous paper(Jahreißet al.2001)we selected red NLTT stars(Luyten’s spectral classes“m”and“m+”) as candidates of nearby stars and obtained more accurate positions and photographic photometry from the APM sky catalogues(Irwin et al.1994).However,the optical colours of these late-type star candidates show only a weak correlation with spectral subclass(Scholz et al.2000). As already mentioned in Jahreißet al.(2001),optical-to-infrared colours are a much better choice.The2MASS data base allows an all-sky search with the input of target lists or by pre-deﬁned search parameters.We have cross-identiﬁed NLTT stars in a region cover-ing about50%of the northern sky(07h<α<19h,δ>0◦) with the2MASS data base.Only bright2MASS sources (K s<10)identiﬁed with faint(Luyten’s R>14.5)NLTT stars within a search radius of60arcsec were further inves-tigated.All identiﬁcations were checked with two epochs of DSS images.In addition to the optical magnitude esti-mates given in the proper motion catalogue,we also ex-tracted the R magnitudes from the A2.0catalogue(Monet et al.1998).The DSS1images usually had the same epoch as the A2.0catalogue,whereas the DSS2images had an epoch close to that of the2MASS data.LHS2090turned out as a candidate nearby star in our ﬁrst sample of about50stars selected for follow-up clas-siﬁcation spectroscopy.With K s=8.4and R−K s=6.4 (USNO-2MASS),LHS2090was one of the most promis-ing objects in the list of candidates.The whole sample of about35objects which was successfully observed spectro-scopically,will be subject of a forthcoming paper.3.Former information on LHS2090LHS2090was detected by Willem Luyten within the scope of his proper motion survey with the48-inch Schmidt tele-scope and got the detection designation LP368-128.Its reﬁned(LHS)proper motion is0.785′′in216.3◦.Willem Luyten’s estimates of its red and photographic magni-tudes are R=15.5and m pg=17.4,respectively.Luyten hoped that the mean error of the magnitudes are not larger than±0.6mag though errors of even1.5do oc-cur(Luyten1964).Having this in mind Luyten’s magni-tudes are in good agreement with the USNO-A2.0values R=14.8and B=17.7,which are also measurements of the POSS-I O and E plates.Aﬁnding chart of LHS2090 was published in the LHS Atlas(Luyten&Albers1979). Luyten attributed a spectral class“m”to this object. Since Luyten’s publication,no additional information on LHS2090became available unless the most recent as-trometric and photometric measurements in USNO-A2.0 and2MASS(09h00m23.s59,+21◦50′05.′′5(J2000at2MASS epoch1998.44)).It was too faint to enter the photometric surveys of LHS stars carried out by Eggen or Weis.4.Spectroscopic distance estimate of LHS2090 Spectroscopic follow-up observations were carried out with CAFOS,the focal reducer and faint objects spectrograph at the2.2m Calar Alto telescope.The grism B-400was used yielding9.6˚A per pixel on the SITe1d CCD and a wavelength coverage from4000˚A to8000˚A.A slit width of 1arcsec was used,corresponding to a spectral resolution of18˚A.The exposure time was60seconds for LHS2090 and120seconds for the bright comparison star GJ1111 (observed during twilight).The spectra were calibrated by standard procedures within the MIDAS package for bias-subtraction,ﬂat-R.-D.Scholz et al.:Search for nearby stars among proper motion stars.I.Discovery of LHS 2090at d ∼6pc3Fig.1.Spectrum of LHS 2090in comparison to that of the well known M6.5star GJ 1111.Both spectra were taken with the 2.2m telescope at Calar Alto.The spectra are nearly identical,and we adopted the spectral type of M6.5for LHS 2090.ﬁelding and wavelength calibration using Ne-Ar lamp spectra.For relative ﬂux calibration we have used spec-tra of secondary spectrophotometric standard stars from Oke &Gunn (1983).The low-resolution spectrum of LHS 2090is nearly identical to that of the known M6.5dwarf GJ 1111(see Figure 1).With that spectral type and taking the mean absolute magnitudes of M6.5dwarfs M J =10.51,M H =9.94,M K s =9.60given in Kirkpatrick &McCarthy (1994),we obtained spectroscopic distance estimates d J =6.06pc,d H =6.07pc,d K s =5.83pc,respectively.A conservative assumtion of ±0.4mag accuracy in absolute magnitude yields 6.0±1.1pc.5.Conclusions1.After the recent discovery of DENIS-P J104817.7-395606.1(Delfosse et al.2001),an M9dwarf at only 4pc spectroscopic distance from the Sun,we have found another very nearby star,LHS 2090,at 6pc.2.Despite its large proper motion (µ=0.785arcsec/yr),LHS 2090had not been further investigated up to now.3.The low-dispersion spectrum of LHS 2090closely re-sembles that of the M6.5star GJ 1111.We conclude therefore that LHS 2090is of spectral type M6.5as well.Hence the distance estimate based on the 2MASS JHK s magnitudes yields d =6pc.Trigonometric par-allax determination and investigation of a possible bi-narity of LHS 2090is needed for conﬁrmation.4.The combination of high proper motion star data with infrared sky surveys such as the 2MASS survey is a very eﬀective tool for ﬁnding previously unknown nearby red dwarfs.Acknowledgements.The spectroscopic conﬁrmation of nearby star candidates is based on observations made with the 2.2m telescope of the German-Spanish Astronomical Centre,CalarAlto,Spain,This research has made use of the SIMBAD database and the VizieR Catalogue Service,Strasbourg,of the STScI Digitized Sky Survey and of data products from the Two Micron All Sky Survey,which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center,funded by the National Aeronautics and Space Administration and the National Science Foundation.We would like to thank Darja Golikowa for her help with the re-identiﬁcation of high proper motion stars in DSS images and their cross-correlation with USNO A2.0and 2MASS data.RDS gratefully acknowledges ﬁnancial support from the Deutsches Zentrum f¨u r Luft-und Raumfahrt (DLR)(F¨o rder-kennzeichen 50OI 0001).We thank the referee,John Gizis,for his prompt report.ReferencesDelfosse X.,Forveille T.,Martin E.L.et al.2001,A&A,366,L13Fleming T.A.1998,ApJ,504,461Gizis J.E.,Reid I.N.1997,PASP,109,849Gizis J.E.,Monet D.G.,Reid I.N.,Kirkpatrick J.D.,LiebertJ.,Williams R.J.2000,AJ,120,1085Gliese W.,JahreißH.1991,Preliminary Version of the ThirdCatalogue of Nearby Stars,computer-readable version on ADC Selected Astronomical Catalogs Vol.1-CD-ROM Henry T.J.,Ianna P.A.,Kirkpatrick J.D.,JahreißH.1997,AJ,114,388Irwin M.J.,Maddox S.J.,McMahon R.G.1994,Spectrum N o .2,14-16JahreißH.,Scholz R.-D.,Meusinger H.,Lehmann I.2001,A&A,370,967Kirkpatrick J.D.,McCarthy D.W.1994,AJ,107,333Leonard P.J.T.,Tremaine S.1990,ApJ,353,486Luyten W.J.1964,Proper motion survey with the 48inchSchmidt telescope.Vol II The North Pole.University of Minnesota,MinneapolisLuyten W.J.1979,LHS Catalogue.Second Edition.Universityof Minnesota,MinneapolisLuyten W.J.1979-1980,New Luyten Catalogue of Stars withProper Motions Larger than Two Tenths of an Arcsecond,University of Minnesota,Minneapolis,computer-readable version on ADC Selected Astronomical Catalogs Vol.1-CD-ROMLuyten W.J.,Albers H.1979,LHS atlas.An atlas of iden-tiﬁcation charts for LHS stars.University of Minnesota,MinneapolisMeillon L.,Crifo F.,Gomez A.,Udry S.,Mayor M.1997,inBattrick B.(ed.),Hipparcos Venice’97,ESA-SP 402,p.591Monet D.,Bird A.,Canzian B.et al.1998,USNO-AV2.0,A Catalog of Astrometric Standards,U.S.Naval Observatory FlagstaﬀStation (USNOFS)and Universities Space Research Association (USRA)stationed at USNOFS Monet D.G.,Fisher M.D.,Liebert J.,Canzian B.,Harris H.C.,Reid I.N.2000,AJ,120,1541Oke J.B.,Gunn J.E.1983,ApJ,266,713Reid I.N.,Kirkpatrick J.D.,Gizis J.E.,Dahn C.C.,MonetD.G.,Williams R.J.,Liebert J.,Burgasser,A.J.2000,AJ,119,369Ruiz M.T.,Wischnjewsky M.,Rojo P.M.,Gonzalez L.E.2001,ApJSS,133,119Scholz R.-D.,Irwin M.,Schweitzer A.,Ibata R.1999,A&A,345,L554R.-D.Scholz et al.:Search for nearby stars among proper motion stars.I.Discovery of LHS2090at d∼6pc Scholz R.-D.,Irwin M.,Ibata R.,JahreißH.,Malkov O.Yu.2000,A&A,353,958。