cluster of galaxies and supercluster
小学上册第十二次英语第一单元真题试卷(含答案)
小学上册英语第一单元真题试卷(含答案)英语试题一、综合题(本题有50小题，每小题1分，共100分.每小题不选、错误，均不给分)1 What is the name of the fairy tale character with long hair?A. CinderellaB. RapunzelC. Snow WhiteD. Sleeping Beauty答案:B2 Every Saturday, I go to my friend's house and we play with our ________ (玩具名) together. It’s always a great time!3 She likes to _____ books. (read)4 My aunt loves __________ (读书).5 The bird is ___ in the sky. (soaring)6 The dolphin leaps out of the _______ (水).7 A __________ is a natural reservoir of water.8 The element with the chemical symbol O is _______.9 The ancient Greeks believed in the importance of ________.10 What do we call the place where we go to buy food?A. StoreB. MallC. MarketD. Warehouse11 What do bees produce?a. Milkb. Honeyc. Eggsd. Silk答案:B12 The __________ is the area where most geological activity occurs.13 A ______ is a type of animal that can walk on two legs.14 What is the name of the famous mountain range in South America?A. RockiesB. AndesC. AlpsD. Himalayas答案:B15 The __________ is essential for maintaining biodiversity.16 Which word means "happy"?a. Sadb. Joyfulc. Angryd. Tired答案:b17 The ______ (小鸭) quacks loudly.18 My ________ (玩具名称) creates lasting joy.19 What do you call the person who writes books?A. DoctorB. TeacherC. AuthorD. Painter答案:C20 My favorite holiday tradition is ______.21 The capital of Ecuador is __________.22 I love to ______ (与朋友一起) plan events.23 What do you call the story of a person's life written by that person?A. BiographyB. AutobiographyC. NovelD. Memoir答案:B24 I have a toy ________ that can sing.25 A ______ (养护) schedule keeps plants healthy.26 A _______ is a property that describes how easily a substance can be magnetized.27 My dad bought me a ________ (篮球) for my birthday, and I love to ________ (打球) with my friends.28 We go to school by ______. (bus)29 We visit the _____ (博物馆).30 The cake is _______ (在烤箱里).31 A __________ is a famous celebration of culture.32 What do you call a collection of poems?A. AnthologyB. CompilationC. CollectionD. All of the above33 The __________ (文化大革命) was a significant era in Chinese history.34 What is the primary ingredient in a traditional risotto?A. RiceB. PastaC. GrainD. Quinoa35 Wall served as a defense against ________ (攻击). The Grea36 Which of these is a dairy product?A. YogurtB. BreadC. RiceD. Pasta37 My ______ is a great cook and loves to bake.38 Atoms are made up of protons, neutrons, and ______.39 What do we call the layer of gases surrounding the Earth?A. AtmosphereB. StratosphereC. LithosphereD. Hydrosphere答案: A40 The __________ (历史的传承者) carry forward the lessons learned.41 What is the primary color that, when mixed with green, creates cyan?A. BlueB. YellowC. RedD. Orange答案:A42 I can ______ (sing) a song for you.43 What is the capital of France?A. BerlinB. MadridC. ParisD. Rome44 The ____ is known for its hopping abilities and long ears.45 My sister has a ______ in her room.46 What is the name of the planet we live on?A. MarsB. JupiterC. EarthD. Venus答案: C47 What is the capital of the USA?A. New YorkB. Los AngelesC. WashingtonD.C.D. Chicago答案：C48 Earth is the only planet known to support ______.49 We like to ________ (build) sandcastles.50 What is the opposite of thin?A. ThickB. SlimC. NarrowD. All of the above答案:A51 The cat purrs when it is ______.52 What is the main ingredient in bread?A. RiceB. WheatC. CornD. Sugar答案: B53 A ______ has a pouch for carrying its baby.54 In a chemical reaction, the substances produced are called ________.55 Do you have any _____ (鸟) at home?56 The ________ (生态系统保护) is paramount.57 How many hours are in a day?A. 22B. 24C. 20D. 18答案:B58 We can plant ______ (树) in our schoolyard. They will provide ______ (阴凉).59 A _____ (土地利用) impacts plant diversity in regions.60 The _______ of a wave can be visualized using a graph.61 What do we call the study of the universe?A. BiologyB. ChemistryC. AstronomyD. Geology答案: C62 In the garden, I saw a _______ (小鸟) singing happily on a branch.63 I can ___ (jump/fly) very high.64 What is the capital of China?A. ShanghaiB. BeijingC. Hong KongD. Guangzhou答案:B65 The _____ (植物群落) varies across different ecosystems.66 I like to _______ my toys before bed.67 My favorite pet is a ______ (兔子) that loves to hop around.68 How do you say "hello" in Spanish?A. BonjourB. HalloC. HolaD. Ciao答案:C69 What is the last letter of the English alphabet?A. XB. YC. ZD. W答案:C70 I enjoy reading ___. (stories)71 I love to decorate my ______ (房间) with posters and photos. It reflects my personality and interests.72 I feed my dog _______ (新鲜的) food every day.73 What is the process of water turning into vapor?A. EvaporationB. CondensationC. PrecipitationD. Sublimation74 My brother has a pet ______ (蜥蜴) that changes color.75 The ________ (城市扩展) causes changes in landscapes.76 The _______ of a wave can be described as its height.77 I enjoy making up stories about my ________ (玩具名称).78 My sister loves to __________ (拍照) during vacations.79 What do you call a person who conducts an orchestra?A. ConductorB. MaestroC. LeaderD. Director答案:A80 What is the term for a group of galaxies?A. ClusterB. SuperclusterC. Galaxy GroupD. Nebula81 The polar bear lives in the _________. (北极)82 The chemical formula for ethanol is ______.83 What is the name of the famous fish in "Finding Nemo"?A. DoryB. MarlinC. NemoD. Bruce答案:C84 The _______ can help improve air quality.85 The __________ is a large body of water surrounded by land. (湖泊)86 What is the main ingredient in chocolate?A. SugarB. CocoaC. FlourD. Milk87 The atomic mass of an element is the average mass of its _____.88 The sun rises in the ______. (east)89 A _____ (骆驼) can survive without water for long periods.90 What is the primary color of a stop sign?A. YellowB. BlueC. RedD. Green答案: C. Red91 My sister is a ______. She enjoys photography.92 My friend has a unique __________ (风格).93 What is the primary function of the heart?A. To digest foodB. To pump bloodC. To filter airD. To produce energy答案:B94 The ancient Greeks practiced democracy in _____.95 The sky is ________ (蓝色) today.96 What is the name of the famous artist known for his portraits?A. Vincent van GoghB. Leonardo da VinciC. Pablo PicassoD. Claude Monet97 A small ___ (小袋鼠) hops around in Australia.98 What do you call a large body of saltwater?A. RiverB. OceanC. PondD. Lake答案:B99 My friend is a _____ (艺术家) who draws comic books. 100 The _______ is where the roots grow.。
关于地球的英语说明文阅读
关于地球的英语说明文阅读Earth: Our Azure Planet.Earth, the third planet from the Sun, is a captivating cosmic gem that has sustained life for billions of years. It is the only known celestial body in the universe that harbors a vibrant ecosystem, making it an object of immense scientific fascination and ecological significance.Aqueous Composition.One of the most defining characteristics of Earth isits abundance of liquid water. Approximately 71% of its surface is covered by oceans, which hold a staggering 96.5% of the planet's water. This aqueous embrace has played a pivotal role in shaping Earth's climate, supporting life, and driving geological processes.Atmospheric Veil.Earth's atmosphere, a gaseous envelope that surrounds the planet, is another crucial aspect of its life-sustaining nature. Composed primarily of nitrogen, oxygen, and argon, the atmosphere protects Earth from harmful solar radiation, regulates temperature, and facilitates the exchange of gases essential for life. It also plays a crucial role in the hydrological cycle, which drives weather patterns and distributes water around the globe.Terrestrial Diversity.Earth's surface is a tapestry of diverse landscapes, from towering mountain ranges to sprawling deserts, lush rainforests to vast polar ice caps. This geological heterogeneity reflects billions of years of tectonic activity, volcanic eruptions, and erosion. The interplay of these forces has created a myriad of habitats, each supporting unique ecosystems and life forms.Dynamic Crust.The Earth's outermost layer, the crust, is divided intotwo main types: oceanic and continental. Oceanic crust is younger and thinner, formed at mid-ocean ridges where new crust is created. Continental crust, on the other hand, is older and thicker, containing a rich history of geological events preserved in its rock formations.Mantle and Core.Beneath the crust lies the mantle, a thick layer of solid rock that makes up the majority of Earth's mass. The mantle is hot and under immense pressure, causing it to slowly flow over millions of years. At the heart of Earth is the core, composed primarily of iron and nickel. The core is extremely hot and dense, generating Earth's magnetic field, which protects the planet from harmful solar radiation.Life on Earth.Earth is the only known planet in the universe that supports life. The diversity of life forms on Earth is staggering, ranging from microscopic organisms to thelargest land and marine animals. This biodiversity is the result of billions of years of evolution, driven by the planet's unique environmental conditions.Environmental Challenges.While Earth has been a nurturing cradle for life, human activities are posing significant environmental challenges. Climate change, deforestation, pollution, and overpopulation are among the pressing issues that threaten Earth's ecosystems and the well-being of its inhabitants. Addressing these challenges requires global cooperation, sustainable practices, and a deep understanding of our planet's delicate balance.Earth's Place in the Cosmos.Earth is a relatively small planet in the vastness of the universe. It orbits the Sun, a star located in one of the spiral arms of the Milky Way galaxy. The Milky Way, in turn, is part of the Local Group of galaxies, which isitself part of the Virgo Supercluster. Earth's place in thecosmos is a humbling reminder of our insignificance in the grand scheme of things, yet it also underscores the preciousness of life on our planet.Conclusion.Earth, our vibrant blue marble, is a marvel of cosmic design. Its aqueous composition, dynamic atmosphere, diverse landscapes, and complex geological processes have created a planet that is uniquely suited for life. As we continue to explore the wonders of our planet and beyond, let us appreciate the fragility and resilience of Earth and strive to preserve its vitality for generations to come.。
小学上册第十四次英语第1单元测验试卷
小学上册英语第1单元测验试卷考试时间：90分钟（总分:120）B卷一、综合题(共计100题共100分)1. 听力题：She has ________ (two) brothers.2. 听力题：The process of a solid turning into a liquid is called ______.3. 听力题：My favorite book is ________.4. 填空题：A turtle moves ______ (慢) but can live a long time.5. 选择题：What do we call the time of year when it snows?A. WinterB. SpringC. SummerD. Autumn6. 填空题：The horse gallops across the ________________ (田野).7. 选择题：Which vegetable is orange and long?A. PotatoB. CarrotC. BroccoliD. Lettuce答案: B8. 填空题：I enjoy playing ______ at home.9. 选择题：What do we call a person who studies physical activity?A. KinesiologistB. PhysiotherapistC. Exercise ScientistD. All of the above10. 听力题：She is _____ (running) in the park.11. 填空题：The ________ (水文条件) affects growth.12. 选择题：Where do fish live?A. TreesB. GroundC. WaterD. Sky答案:C13. 填空题：I enjoy ______ (与朋友一起) going to concerts.14. 听力题：This is my ____ (brother). He is years old.15. 听力题：His hair is ________.16. 听力题：They are _____ (drawing) with chalk.17. 填空题：A __________ day is great for a family outing. (欢快的)18. 选择题：What is the main purpose of a space probe?A. To carry humans into spaceB. To collect data about celestial bodiesC. To photograph the EarthD. To study weather patterns19. 选择题：What do you call a collection of galaxies?A. ClusterB. SuperclusterC. UniverseD. Cosmos答案:B20. 选择题：What is the name of the famous bear from Canada?A. PaddingtonB. Winnie-the-PoohC. Yogi BearD. Baloo21. 选择题：Which device do we use to call someone?A. TelevisionB. PhoneC. RadioD. Computer22. 听力题：__________ are used to balance chemical equations.23. 听力题：He is a good ________ player.24. 填空题:I enjoy playing ________ after school with my friends.25. 填空题：She has a _______ who is very tall.26. 听力题：The gas we breathe in is ______.27. 听力题：A ______ is a type of energy that can cause changes in matter.28. 选择题：What is the opposite of 'hard'?A. ToughB. SoftC. FirmD. Solid答案:B29. 听力题：A ____ is a tiny creature that loves to hop around.30. 填空题：The ______ (蟑螂) hides in dark places during the day.31. 选择题：What is the color of an orange?A. GreenB. YellowC. OrangeD. Red答案:C32. 填空题:I like to plant ________ in the garden.33. 听力题：__________ are mixtures that can be easily separated.34. 填空题：The __________ (历史的推动) inspires change.35. 听力题：The process of photosynthesis occurs in the _______ of plant cells.36. 填空题：My dad encourages me to be __________ (开放的) to opportunities.37. 选择题：What do you call a baby dog?a. Kittenb. Puppyc. Cubd. Calf答案:b38. ts have medicinal ______ that can help treat illnesses. (一些植物具有药用特性，可以帮助治疗疾病。
剑桥商务英语听说 星系
剑桥商务英语听说星系The Milky Way GalaxyThe Milky Way is the galaxy that contains our Solar System, with the Earth and Sun. This galaxy is a vast, spinning collection of stars, planets, dust and gas, held together by gravity. It is just one of hundreds of billions of galaxies in the observable universe.The Milky Way galaxy is estimated to contain 100-400 billion stars and have a diameter between 100,000 and 180,000 light-years. It is the second-largest galaxy in the Local Group, with the Andromeda Galaxy being larger. As with other spiral galaxies, the Milky Way has a central bulge surrounded by a rotating disk of gas, dust and stars. This disk is approximately 13 billion years old and contains population I and population II stars.The solar system is located about 25,000 to 28,000 light-years from the galactic center, on the inner edge of one of the spiral-shaped concentrations of gas and dust called the Orion Arm. The stars in the Milky Way appear to form several distinct components including the bulge, the disk, and the halo. These components are made of different types of stars, and differ in their ages and their chemicalabundances.The Milky Way galaxy is part of the Local Group, a group of more than 50 galaxies, including the Andromeda Galaxy and several dwarf galaxies. The Local Group in turn is part of the Virgo Supercluster, a giant structure of thousands of galaxies. The Milky Way and Andromeda Galaxy are moving towards each other and are expected to collide in about 4.5 billion years, although the likelihood of any actual collisions between the stars themselves is negligible.The Milky Way has several major arms that spiral from the galactic bulge, as well as minor spurs. The best known are the Perseus Arm and the Sagittarius Arm. The Sun and its solar system are located between two of these spiral arms, known as the Local Bubble. There are believed to be four major spiral arms, as well as several smaller segments of spiral arms.The nature of the Milky Way's bar and spiral structure is still a matter of active research, with the latest research contradicting the previous theories. The Milky Way may have a prominent central bar structure, and its shape may be best described as a barred spiral galaxy. The disk of the Milky Way has a diameter of about 100,000 light-years. The galactic halo is a spherical component of the galaxy that extends outward from the galactic disk, as far as 200,000 light-years from the galactic center.The disk of the Milky Way Galaxy is marked by the presence of a supermassive black hole known as Sagittarius A*, which is located at the very center of the Galaxy. This black hole has a mass four million times greater than the mass of the Sun. The Milky Way's bar is thought to be about 27,000 light-years long and may be made up of older red stars.The Milky Way is moving with respect to the cosmic microwave background radiation in the direction of the constellation Hydra with a speed of 552 ± 6 km/s. The Milky Way is a spiral galaxy that has undergone major mergers with several smaller galaxies in its distant past. This is evidenced by studies of the stellar halo, which contains globular clusters and streams of stars that were torn from those smaller galaxies.The Milky Way is estimated to contain 100–400 billion stars. Most stars are within the disk and bulge, while the galactic halo is sparsely populated with stars and globular clusters. A 2016 study by the Sloan Digital Sky Survey suggested that the number is likely to be close to the lower end of that estimate, at 100–140 billion stars.The Milky Way has several components: a disk, in which the Sun and its planetary system are located; a central bulge; and a halo of stars, globular clusters, and diffuse gas. The disk is the brightest part of theMilky Way, as seen from Earth. It has a spiral structure with dusty arms. The disk is about 100,000 light-years in diameter and about 13 billion years old. It contains the young and relatively bright population I stars, as well as intermediate-age and old stars of population II.The galactic bulge is a tightly packed group of mostly old stars in the center of the Milky Way. It is estimated to contain tens of billions of stars and has a diameter of about 10,000 light-years. The Milky Way's central bulge is shaped like a box or peanut. The galactic center, which lies within this bulge, is an extremely active region, with intense radio source known as Sagittarius A*, which is likely to be a supermassive black hole.The Milky Way's halo is a spherical component of the galaxy that extends outward from the galactic disk, as far as 200,000 light-years from the galactic center. It is relatively sparse, with only about one star per cubic parsec on average. The halo contains old population II stars, as well as extremely old globular clusters.The Milky Way's spiral structure is uncertain, and there is currently no consensus on the nature of the Milky Way's spiral arms. Different studies have led to different results, and it is unclear whether the Milky Way has two, four, or more spiral arms. The Milky Way's spiral structure is thought to be a major feature of its disk, and it may berelated to the generation of interstellar matter and star formation.The Milky Way's spiral arms are regions of the disk in which the density of stars, interstellar gas, and dust is slightly higher than average. The arms are thought to be density waves that spiral around the galactic center. As material enters an arm, the increased density causes the material to accumulate, thus causing star formation. As the material leaves the arm, star formation decreases.The Milky Way's spiral arms were first identified in the 1950s, when radio astronomers mapped the distribution of gas in the Milky Way and found that it was concentrated in spiral patterns. Since then, astronomers have used a variety of techniques to study the Milky Way's spiral structure, including observations of the distribution of young stars, star-forming regions, and interstellar gas and dust.One of the key challenges in studying the Milky Way's spiral structure is that we are located within the disk of the galaxy, which makes it difficult to get a clear view of the overall structure. Astronomers have had to rely on indirect methods, such as measuring the distances and motions of stars and gas clouds, to infer the shape and structure of the galaxy.Despite these challenges, our understanding of the Milky Way's spiral structure has advanced significantly in recent years, thanks tonew observations and more sophisticated modeling techniques. Ongoing research is continuing to shed light on the nature and evolution of the Milky Way's spiral arms, and the role they play in the overall structure and dynamics of the galaxy.。
小学上册第十四次英语第2单元真题
小学上册英语第2单元真题英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.My _____ (表妹) enjoys playing with her stuffed animals every day. 我表妹每天都喜欢玩她的毛绒玩具。
2. A compound is a substance formed when two or more elements are _____ chemically.3. A kitten's purring is very ______ (放松).4.He is a musician, ______ (他是一位音乐家), playing in a local band.5.What do we call the place where we watch movies?A. TheaterB. MuseumC. LibraryD. Park6.I enjoy _____ (reading/watching) movies.7. A ______ has a symbiotic relationship with flowers.8.Protecting endangered ______ (植物物种) is vital for preservation.9.The rainbow trout is a beautiful _________ (鱼).10.My sister is a _____ (演员) who loves performing.11.The ____ is a gentle giant that enjoys eating grass.12.What do we call a written record of someone's life?A. BiographyB. AutobiographyC. MemoirD. Journal13.In ancient China, the __________ Dynasty was known for its inventions. (汉朝)14.My sister has a knack for ____ (fashion).15.The ____ has a distinctive call and can be loud.16.What do you call an animal that eats both plants and meat?A. HerbivoreB. CarnivoreC. OmnivoreD. InsectivoreC17.The __________ (历史的测试) assesses understanding.18.The _____ (糖果) is very sweet.19.My brother is learning to play the ____ (accordion).20.The __________ is a region known for its festivals.21.I think learning about different cultures expands our __________.22.The __________ helps to protect the brain.23.I love to paint my toy ____ in bright colors. (玩具名称)24. A _______ can be very useful in cooking.25.I enjoy playing ________ (乒乓球) in the park. It helps me stay ________ (健康).26.My brother is a ______. He enjoys building things.27.The __________ is a major mountain range that runs through Asia. (喜马拉雅山脉)28. A _______ is a great addition to any garden.29.My brother is known for his __________ (勇气).30.Which fruit is known for having seeds on the outside?A. StrawberryB. BlueberryC. RaspberryD. BlackberryA31.The leaves change _______ in the fall, creating a beautiful view.32.Certain types of grass are perfect for ______. (某些类型的草非常适合草坪。
50个星系小知识
50个星系小知识1. 银河系（Milky Way）：我们所在的星系，包含数百亿颗星星。
2. 仙女座星系（Andromeda Galaxy）：是离我们最近的大型螺旋星系，将在未来几十亿年内与银河系发生碰撞。
3. 大麦哲伦星云（Large Magellanic Cloud）：是银河系的伴随星云，可在南半球看到。
4. 小麦哲伦星云（Small Magellanic Cloud）：也是银河系的伴随星云，位于大麦哲伦星云附近。
5. 三角座大星系团（Triangulum Galaxy）：是本地群中的第三大星系，与银河系和仙女座星系一同组成本地群。
6. M87星系：包含了世界首张黑洞照片的星系，黑洞称为M87*。
7. 半人马座α星系（Alpha Centauri）：是距离地球最近的三颗恒星，包括Proxima Centauri。
8. 螺旋星云（Whirlpool Galaxy）：与伴随星系NGC 5195一同构成一对交互作用的星系。
9. 和平座流星团（Pleiades）：一群年轻的恒星，以七姐妹而闻名。
10. 狮子座不规则星系（Leo I）：是银河系的卫星星系之一。
11. NGC 1300：一座螺旋星系，以其引人注目的臂旋结构而著称。
12. 椭圆星系（Elliptical Galaxy）：具有椭圆形状的星系，通常由老年恒星组成。
13. 蝎子座X-1：包含一颗质量极大的恒星和一个紧密伴星，是X射线双星系统。
14. NGC 2244：位于猎户座大星云中的一个年轻星团。
15. 哈勃深空场（Hubble Deep Field）：是哈勃太空望远镜拍摄的一个小区域，显示了许多远离地球的星系。
16. 蓝色大理石星系（Blue Marble Galaxy）：以其蓝色的颜色而闻名，是由气体和尘埃组成的星系。
17. NGC 6822：也称为巧克力盒星系，是一个不规则星系。
18. 奇迹星系（Antennae Galaxies）：两个星系之间发生碰撞，形成引人注目的星系相互作用。
小学下册第13次英语第6单元真题试卷[有答案]
小学下册英语第6单元真题试卷[有答案]英语试题一、综合题(本题有50小题，每小题1分，共100分.每小题不选、错误，均不给分)1 The ________ (exhibit) shows historical artifacts.2 What is the main ingredient in mayonnaise?A. OilB. VinegarC. Egg yolkD. Sugar3 How many hours are in a day?A. 12B. 24C. 36D. 484 How many hours are in a day?A. 24B. 12C. 36D. 48答案:A5 Molecules are made up of two or more _____ bonded together.6 I have a green ___. (ball)7 A ____(habitat) can be destroyed by pollution.8 Which fruit is known for having seeds on the outside?A. BananaB. StrawberryC. AppleD. Grape答案: B9 I can ______ (表达) my ideas confidently.10 What do you call a frozen dessert made from cream?A. CakeB. Ice creamC. PuddingD. Pie答案:B11 The ancient civilization of ________ is known for its monumental structures.12 _____ (herbivore) animals eat plants.13 The kitten plays with a _______ (小猫玩_______).14 I like to eat ___. (fruit)15 The chemical symbol for barium is _______.16 The capital of Japan is __________. (东京)17 In autumn, leaves __________ (变色).18 A reactant is a substance that takes part in a ______ reaction.19 The artist expresses emotions through _____ (艺术).20 What is the name of the mineral used to make salt?A. CalciumB. SodiumC. PotassiumD. Magnesium21 Do you like to watch _____ (蝴蝶) in the garden?22 What do you call a large, round fruit that is typically orange?A. AppleB. PeachC. OrangeD. Banana23 The _______ can help improve air quality.24 The ________ was a key event in the history of civil rights in the United States.25 He is running very ___. (fast)26 Which bird is known for its colorful feathers and ability to mimic sounds?A. CrowB. ParrotC. SparrowD. Eagle答案:B27 We eat _____ (breakfast/lunch) at AM.28 The __________ (历史的本质) is unveiled through inquiry.29 The fox is known for its _________. (狡猾)30 Understanding the role of plants in our environment is crucial for ______. (了解植物在环境中的作用对保护至关重要。
小学上册第十五次英语下册试卷
小学上册英语下册试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.Plant cells have a ______ (细胞壁) that protects them.2.War was marked by the fear of ________ (核战争). The Colo3.I am learning how to ________ (游泳) this summer.4.My dad is a _____ (工程师) who designs transportation systems.5.The ______ (根茎) of ginger is used in cooking.6.I always greet my parents in the morning by saying . (早上我总是向父母问好，说。
)7.The park is _______ (适合家庭).8.I love spending time outdoors. Activities like __________ help me appreciate nature and stay active. It’s refreshing to breathe in the fresh air.9.What is the opposite of "fast"?A. SlowB. QuickC. SpeedyD. Rapid10. A _____ is a low area of land between hills.11.The ________ was a crucial chapter in the narrative of national unity.12.What do we use to see in the dark?A. FlashlightB. MirrorC. WindowD. Lamp13.They are playing ______ (hide-and-seek) outside.14.I drink _____ (water/coffee) with lunch.15. A _______ change affects only the form of a substance, not its composition.16.The main product of cellular respiration is _____.17.What do you call the place where you go to learn?A. StoreB. SchoolC. FactoryD. Office18.I can’t wait to show my friends my __________ (玩具名).19.The chemical symbol for cesium is ______.20.What is the name of the phenomenon that occurs when the moon is directly in line with the sun?A. Solar EclipseB. Lunar EclipseC. Total EclipseD. Partial Eclipse21.Tom is a ______. He loves to play soccer.22.What is the main source of energy for plants?A. SoilB. WaterC. SunlightD. Air23.What is the capital city of Turkey?A. IstanbulB. AnkaraC. IzmirD. Antalya24.I enjoy ______ (参加) school events.25.My grandfather, ______ (我的祖父), tells great stories from the past.26. A solid has a ______ shape.27.The __________ (历史的传达过程) ensures continuity.28.My _______ (金鱼) swims in circles.29.The _____ (花草茶) is made from dried plants.30.What do you call the young of a whale?A. CalfB. PupC. KitD. FawnA31.We will go ______ during the summer. (camping)32.How many legs does a spider have?A. 6B. 8C. 10D. 1233.What do you call the festival celebrated in October?A. ChristmasB. HalloweenC. EasterD. Thanksgiving34.What is the name of the plant that produces flowers?A. TreeB. ShrubC. HerbD. BloomD35.What is the term for a group of galaxies held together by gravity?A. Galaxy ClusterB. SuperclusterC. Galaxy GroupD. Cosmic Cluster36.What is the common term for the period of time it takes for the Earth to revolve around the sun?A. DayB. WeekC. MonthD. YearD37.What do we call the scientific study of life?A. BiologyB. ChemistryC. PhysicsD. GeologyA Biology38.The wind makes everything feel ______ (凉爽).39.My favorite season is ______ (春天) because of the flowers.40.I can ______ (处理) conflicts peacefully.41.What is the capital city of Brazil?A. Rio de JaneiroB. BrasiliaC. Sao PauloD. Salvador42.What do we call the person who teaches us at school?A. PrincipalB. TeacherC. StudentD. Janitor43. A ________ (国家公园) protects nature and wildlife.44.The __________ shows how rocks are formed and transformed.45.Bees help ______ plants by pollinating.46.The classroom is very ________.47.The Earth's crust is shaped by both climatic and ______ factors.48.The rabbit's _______ (耳朵) are very sensitive.49.The stars are ___ (twinkling/shining).50.I love going to science fairs to see innovative __________.51.What is the capital of Sweden?A. StockholmB. GothenburgC. MalmöD. UppsalaA52.The cake is ________ (sweet) and delicious.53.The girl is very ________.54.Tectonic plates can move apart, collide, or slide past each other, leading to ______.55.What do you call the distance around a circle?A. DiameterB. RadiusC. CircumferenceD. AreaC56.What sound does a dog make?A. MeowB. RoarC. BarkD. Moo57.What is the name of the famous American holiday celebrated on the fourth Thursday in November?A. ThanksgivingB. ChristmasC. New Year'sD. Independence DayA58.I planted a _____ (向日葵) in my garden. It turns towards the sun. 我在花园里种了一朵向日葵。
Chapter 14Our Galaxy
Radiation from newly formed stars is eroding these starforming clouds
Summary of Galactic Recycling
• Stars make new elements by fusion • Dying stars expel gas and new elements, producing hot bubbles (~106 K) • Hot gas cools, allowing atomic hydrogen clouds to form (~100-10,000 K) • Further cooling permits molecules to form, making molecular clouds (~30 K) • Gravity forms new stars (and planets) in molecular clouds
Our Parent Galaxy cont
Much of what we think we know of our galaxy comes from the study of other galaxies similar to our own. Ours is a spiral or more likely a barred spiral galaxy. All spiral galaxies have a Galactic bulge and disk embedded in a roughly spherical ball of faint old stars called the Galactic halo.
High-mass stars have strong stellar winds that blow bubbles of hot gas