(人教版2017课标)高中英语必修第二册：Unit 2单元测试(含答案)
Unit 2 单元测试一、阅读理解（共两节，满分35分）第一节（共10小题，每小题2.5分，满分25分）阅读下列短文，从每题所给的A、B、C和D四个选项中，选出最佳选项。
AMore than two thirds of the world’s polar bears will be wiped out by 2050, according to ashocking new study. By then, scientists say, global warming will have melted 42 percent of theArctic sea ice. By 2100, only a very few of these important creatures will be left.The report has been produced by the US Geological Survey. The scientists have publicizedtheir findings in the hope of influencing US Interior Secretary Dirk Kempthorne, who has beenasked to put polar bears on the US endangered species list.Polar bears depend on floating sea ice as a platform for hunting seals, which are their main food. Without enough ice, polar bears would be forced to go onto the land, where they are killed by hunters, and would be unlikely to adapt to the life on the land in time. Experts say few little bears would survive and the stress could make many females unable to get pregnant.The team of American and Canadian scientists spent six months studying bears: on the ground, from spotter planes and in the lab, using computer models. Some team members fear the result is even worse for the bears than what their report says. They say the Arctic is warming faster than anywhere in the world and much faster than their computer had been forecasting, Satellite observations have showed that the ice has decreased to an all-time low.However, not everyone in the scientific community believes that global warming is happening on such an alarming scale. Another investigation has found that polar bears are still being hunted by wealthy “sportsmen” who want their skins and heads. At least ten international companies offer bear-hunting trips.1. What do we know about Dirk Kempthorne according to the passage?A. He is an animal scientist.B. He is a protector of animals working for the US government.C. He was asked to put polar bears on the US endangered species list.D. He offered to put polar bears on the endangered species list.2. Why will polar bears die out if there is not enough sea ice?A. Because polar bears can’t catch enough food without sea ice.B. Because polar bears eat ice when they feel thirsty.C. Because polar bears will be easily found by hunters without ice.D. Because most female bears are used to giving birth under ice.3. After a six-month study, some scientists fear that ________.A. there is something wrong with their computersB. polar bears will disappear even faster than they ever expectedC. their computer models are not as accurate as they expectedD. global warming will destroy everything in the ArcticBThe British are known for their sense of humor. However, it is often difficult for foreigners to understand their jokes. The main point to remember is that the British often use understatement.Understatement means saying less than you think or feel. For example, if someone gets very wet in a shower of rain, he might say, “It’s a little damp（潮湿的）outside.” Or, if someone is very impolite and shouts at another person, someone else might say, “She isn’t exactly friendly.” Understatement is often used in an unpleasant situation or to make another person look silly. Understatement plays an important part in British humor.Another key to understanding British humor is that the British like to make fun of themselves as well as others. They often laugh about the silly and unpleasant things that happen to our everyday life when someone accidently falls over in the street. They also like to make jokes about people from different classes of society. They like to make jokes about their accents, the way they dress and the way they behave. What’s more, the British love to watch comedies（喜剧）about people who do not know how to behave in society. The comedies series Mr. Bean is a good example of this kind of humor.Mr. Bean is the character created by British actor Rowan Atkinson in 1990. Mr. Bean doesn’t talk often, and instead he uses his body movement and facial expressions to make people laugh. Perhaps what makes Mr. Bean so funny is that he does things that adults in the real world cannot do. Mr. Bean is popular in many countries around the world because you do not have to speak English to understand the humor. Because of this, many people have become familiar with the British sense of humor.4. Why is it difficult for foreigners to understand British jokes?A. The British often enlarge the fact.B. British jokes are connected with many different cultures.C. British jokes are not as funny as jokes in other countries.D. The British try to make out that something is less important than it is.5. The author explains understatement by ________.A. describing a processB. making comparisonsC. following time orderD. using examples6. What can be the best title for the text?A. British Humor in ComedyB. Humor in Different CulturesC. Understanding British HumorD. Developing Your Sense of HumorCWhere do the turtles go?Every summer, thousands of endangered green sea turtles climb onto beaches around the world. Each mother sea turtle produces 100 or more eggs in a hole, and covers the hole with sand before she swims away.Two months later, the eggs hatch, and the baby turtles climb out of the sand andswim into the ocean. They don’t reappear until they have grown as large as dinner plates.Until now, no one knows where the baby turtles go or what they do.“If we don’t know where these little turtles are, we can’t protect them,” says KimReich, who helps solve part of the mystery.Her teacher, Karen Bjorndal, has studied green sea turtles for more than 30 years.Every year, Bjorndal goes to the Bahamas Islands. Many young sea turtles come here tolive and eat at the end of their childhood.These turtles are the only sea turtles that live as plant eaters. In fact, their name may be a result of what they eat. The turtles don’t look green but they do have green fat. Scientists learned that the turtles eat green sea plants, which may turn their fat green.Between 2002 and 2004, Bjorndal caught 44 green sea turtles in the Bahamas. After testing them, she found something to support the 20-year-old idea: baby green sea turtles eat meat before they turn to a diet of plants. In fact, they eat animals that live in the open ocean.Scientists still need to find where exactly green sea turtles grow. We now know that baby green sea turtles are out in the open ocean, but the open ocean is a big place.“It is really a problem,” says Bjorndal. The discovery may help us do a better job of protecting this sea animal.7. What can we learn from the first two paragraphs?A. Baby turtles go to the ocean when they are three months old.B. Mother turtles leave the eggs alone after they produce them.C. No one knows when turtles appear on the beach.D. Mother turtles are as large as dinner plates.8. Kim Reich does research on where baby turtles go because she wants to ________.A. help her teacherB. prove an ideaC. protect turtlesD. become a scientist9. What does Karen Bjorndal’s research prove about green sea turtles?A. The young live in the Bahamas Islands.B. The young eat meat before turning to a diet of plants.C. They live in the open ocean for a lifelong time.D. They are the only sea turtles that live as plant eaters.10. What does the underlined word “It” in the last paragraph refer to?A. Finding out where young turtles grow.B. Protecting this endangered sea animal.C. Changing young turtles’ eating habits.D. Living in the open ocean.第二节（共5小题；每小题2分，满分10分）根据短文内容，从短文后的选项中选出能填入空白处的最佳选项，选项中有两项为多余选项。
高中英语(新人教版)必修第二册课后习题：UNIT 2 Section B(课后习题)【含答案及解析】
UNIT2WILDLIFE PROTECTIONSection B Reading and Thinking课后篇巩固提升必备知识基础练Ⅰ.单句填空1.If you get to the hotel in the afternoon,please don’t forget(reserve) a room for me.2.On first seeing the city,most visitors are overpowered by the (beautiful) of the noble buildings.3.(observe) carefully if any change occurs when doing experiments in the lab.4.The boy(attack) by a dog when he was walking along the street.5.I think we should also take(effect) measures to make our country more beautiful.6.(remove) clothing using scissors if necessary unless it is stuck to the burn.7.The destruction of the rainforest(threaten) human life.8.Rare animals such as the giant panda should be put protection.9.The experiment has ruled out the possibility of the(exist) of any life on that planet.Ⅱ.短语填空1.Jim is so near-sighted that he can’t what the teacher has written on the blackboard.2.I have a dream that humans could live the beautiful nature.3.The ancient wooden towers which are have been restored beautifully to attract foreigners.4.The American girl the beauty of Mount Tai and decided to stay another day.5.Learning without thinking leads to confusion;thinking without learning ends .6.A notice was set up in order to the students the changed lecture time.7.They use specially trained dogs to their sheep at night.8.The patient has been attended on by nurses since the operation.Ⅲ.翻译句子1.他不够高,够不到树上的苹果。
2020-2021学年英语人教版(2019)必修第二册 Unit 2 同步测试
Unit 2 Wildlife Protection单元测试I. 听力部分第一节听下面5段对话。
每段对话后有一个小题，从每题所给的A、B、C三个选项中选出最佳选项。
每段对话仅读一遍。
( ) 1．What is the time now?A. 7:00.B. 7:30.C. 8:00.( ) 2．Where is the conversation probably taking place?A. In a shop.B. In a hotel.C. In a restaurant.( ) 3．What did the man think of the party?A. He liked it a lot.B. He didn’t think it was good.C. He preferred the party to a movie.( ) 4．What does the man encourage the woman to do?A. Do some sports.B. Eat out.C. Lose weight.( ) 5．What are the speakers doing?A. Fixing a time to meet.B. Talking about a research paper.C. Discussing their homework.第二节听下面一篇短文，回答第6至10题。
这篇短文读两遍。
( ) 6．Which insect is as common as flies and mosquitoes in the text?A. Yellow-faced bees.B. Bees.C. Non-native bees.( ) 7．What types of bees have been placed on the endangered species list in the US?A. Leafcutter bees.B. Sweat bees.C. Yellow-faced bees.( ) 8．Where do the endangered species of bees come from?A. California.B. Washington D.C. C. Hawaii.( ) 9．What’s the cause of the reduction (减少) in the number of bees?A. Habitat loss.B. Native insects.C. Global warming. ( ) 10．What can we infer from the words of Karl Magnacca?A. Bees are helpful to nature and humans.B. Bees are the natural enemy of mosquitoes.C. Bees bring pollen (花粉) to various fruits and vegetables.II. 基础知识一、根据所提供的语境和首字母提示写出完整的单词。
人教版高中英语选择性必修第二册第二单 unit2 reading课件
_虽__然__有__些__外__国__学__生__住__在__学__校__宿__舍__，__但__谢__蕾__选__择__了__住__在__寄____ _宿__家__庭__，__因__为__寄__宿__家__庭__可__以__帮__助__她__适__应__新__文__化__。__________
Translation
Scanning: Choose the best answers according to the passage.
4. Living with the host families can give students_________. ( ) A. the opportunity to go around the new country B. the opportunity to learn the culture in the new country C. the opportunity to get a business qualification D. the opportunity to pass the preparation course
Also Xie Lei had to satisfy academic requirements. Her tutor told her to acknowledge
深圳市高级中学必修第二册第二单元《复数》测试题(含答案解析)
一、选择题1．213(1)ii +=+（ ） A ．3122i - B ．3122i + C ．3122i -- D ．3122i -+ 2．若复数()234sin 12cos z i θθ=-++为纯虚数，()0,θπ∈，则θ=（ ）A ．6π B ．3π C ．23π D ．3π或23π 3．设复数z 满足()13i z i +=+，则z =（ ）A B ．2C ．D 4．若复数z 满足(1)|1|z i i i -=-+，则z 的实部为（ ）A ．12B 1C ．1D ．125．已知下列三个命题：①若复数z 1，z 2的模相等，则z 1，z 2是共轭复数；②z 1，z 2都是复数，若z 1+z 2是虚数，则z 1不是z 2的共轭复数；③复数z 是实数的充要条件是z z =.则其中正确命题的个数为( ) A ．0个 B ．1个 C ．2个 D ．3个 6．已知i 为虚数单位，（1＋i ）x ＝2＋yi ，其中x ，y ∈R ，则｜x ＋yi ｜＝A ．B ．2C ．4D7．设复数z 满足()1i i z +=，则z =（ ）A ．2B ．12CD ．28．在下列命题中，正确命题的个数是（ ） ①两个复数不能比较大小；②复数1z i =-对应的点在第四象限；③若22(1)(32)x x x i -+++是纯虚数，则实数1x =±；④若221223()()0z z z z -+-=，则123z z z ==.A ．0B ．1C ．2D ．39．已知复数z 满足()211i i z+=-(i 为虚数单位），则复数z =（ ）A ．1i +B ．1i -+C ．1i -D ．1i --10．已知复数z 满足()12i z i -=+，则z 的共轭复数在复平面内对应的点在( ) A ．第一象限B ．第二象限C ．第三象限D ．第四象限11．已知复数21aiz i+=-是纯虚数，则实数a 等于（ ） A ．5B ．2C ．3D ．212．对于给定的复数0z ，若满足042z i z z -+-=的复数z 对应的点的轨迹是椭圆，则01z -的取值范围是（ ）A ．()172,172-+ B ．()171,171-+ C ．()32,32-+D ．()31,31-+二、填空题13．已知复数z 满足1z =，则2z i -（其中i 是虚数单位）的最小值为____________.14．如果复数212bii-+的实部和虚部互为相反数，那么实数b 的值为__ 15．若有两个数，它们的和是4，积为5，则这两个数是________.16．已知复数34z i =+所对应的向量为OZ ，把OZ 依逆时针旋转θ得到一个新向量为1OZ ．若1OZ 对应一个纯虚数，当θ取最小正角时，这个纯虚数是________．17．已知复数（，是虚数单位）的对应点在第四象限，且，那么点在平面上形成的区域面积等于____18．已知复数z 满足等式1i 1z --=，则3z -的最大值为______ 19．已知复数z 满足(12)43i z i +=+，则z = _________________； 20．已知|z|=3,且z+3i 是纯虚数,则z=________.三、解答题21．已知复数()212(24)z a a i =--+，()221z a a i =-+，12z z z =-（i 为虚数单位，a R ∈）.（1）若复数12z z z =-为纯虚数，求12z z ⋅的值； （2）若1z z i +=-，求z i +的值.22．已知复数1z mi =+（i 是虚数单位，m R ∈），且(3)z i ⋅+为纯虚数（z 是z 的共轭复数）． （1）设复数121m iz i+=-，求1z ； （2）设复数20172a i z z-=，且复数2z 所对应的点在第一象限，求实数a 的取值范围．23．复数()()()2152615z i m i m i =++-+-．（1）实数m 取什么数时，z 是实数； （2）实数m 取什么数时，z 是纯虚数；（3）实数m 取什么数时，z 对应的点在直线70x y ++=上．24．若z C ∈，i 为虚数单位，且|22|1z i +-=，求|22|z i --的最小值.25．已知z 为虚数，42z z +-为实数． （1）若2z -为纯虚数，求虚数z ；（2）求|4|z -的取值范围．26．已知复数()()21,,z a i bi a b R =+-∈，其中i 是虚数单位. （1）若5z i =-，求a ，b 的值；（2）若z 的实部为2，且0a >，0b >，求证：214a b+≥.【参考答案】***试卷处理标记，请不要删除一、选择题 1．A 解析：A 【分析】首先计算2(1)i +，之后应用复数的除法运算法则，求得结果. 【详解】()21313312221ii i i i ++==-+， 故选A. 【点睛】该题考查的是有关复数的运算，属于简单题目.2．B解析：B 【解析】分析：由题意得到关于sin ,cos θθ的方程组，求解方程组结合题意即可求得三角函数值，由三角函数值即可确定角的大小.详解：若复数()23412z sin cos i θθ=-++为纯虚数，则：234sin 012cos 0θθ⎧-=⎨+≠⎩，即：23sin 41cos 2θθ⎧=⎪⎪⎨⎪≠-⎪⎩，结合()0,θπ∈，可知：sin 21cos 2θθ⎧=⎪⎪⎨⎪=⎪⎩，故3πθ=. 本题选择B 选项.点睛：本题主要考查纯虚数的概率，三角函数的性质及其应用等知识，意在考查学生的转化能力和计算求解能力.3．D解析：D 【解析】分析：先根据复数除法得z ，再根据复数的模求结果. 详解：因为()13i z i +=+，所以31(3)(1)212i z i i i i +==+-=-+,因此z = 选D.点睛：首先对于复数的四则运算，要切实掌握其运算技巧和常规思路，如()()()(),(,,.)++=-++∈a bi c di ac bd ad bc i a b c d R . 其次要熟悉复数相关基本概念，如复数(,)a bi a b R +∈的实部为a 、虚部为b(,)a b 、共轭为.-a bi4．A解析：A 【解析】 【详解】∵()11z i i i i -=-+，∴)()()()111i i z i i +===-+，则z的实部为12，故选A. 5．C解析：C 【分析】运用复数的模、共轭复数、虚数等知识对命题进行判断. 【详解】对于①中复数1z 和2z 的模相等,例如1=1+z i,2z ,则1z 和2z 是共轭复数是错误的;对于②1z 和2z 都是复数,若12+z z 是虚数,则其实部互为相反数,则1z 不是2z 的共轭复数,所以②是正确的;对于③复数z 是实数,令z a =,则z a =所以z z =,反之当z z =时,亦有复数z 是实数,故复数z 是实数的充要条件是z z =是正确的.综上正确命题的个数是2个. 故选C 【点睛】本题考查了复数的基本概念,判断命题是否正确需要熟练掌握基础知识,并能运用举例的方法进行判断,本题较为基础.6．A解析：A 【解析】 【分析】首先求得x ,y 的值，然后求解复数的模即可. 【详解】由题意可得：2x xi yi +=+，结合复数的充分必要条件可知：2x x y =⎧⎨=⎩，则2x y ==，22x yi i +=+== 本题选择A 选项. 【点睛】本题主要考查复数相等的充分必要条件，复数模的求解等知识，意在考查学生的转化能力和计算求解能力.7．A解析：A 【解析】由()1i z i +=，得()()()i 1i i 11i 1i 1i 1i 22z -=+++-＝＝，2z ∴=＝故选A ． 8．A解析：A 【解析】对于选项①,不能说两个复数不能比较大小，如复数3和4就可比较大小，所以该命题是错误的.对于选项②，复数1z i =-对应的点在第二象限，所以该命题是错误的.对于选项③，若()()22132x x x i -+++是纯虚数，则21x -=0且232x x ++≠0，所以x=1,所以该命题是错误的. 对于选项④，若()()2212230z z z z -+-=，可以123,0,1z i z z ===， 所以该命题是错误的. 故选A.9．B解析：B 【解析】因为()211i i z+=-，所以22(1)112i iz i i i ==+=-- ，选B. 10．D解析：D 【解析】()12i z i -=+，()()()()1i 1i 2+i 1i z ∴-+=+，13213i,i,22z z =+=+13i,22z z=-的共轭复数在复平面内对应点坐标为13,22⎛⎫- ⎪⎝⎭，z 的共轭复数在复平面内对应的点在第四象限，故选D.11．B解析：B 【分析】 化简复数2222a a z i -+=+，根据复数z 是纯虚数，得到202a -=且202a+≠，即可求解. 【详解】由题意，复数()()()()2122211122ai i ai a az i i i i +++-+===+--+， 因为复数z 是纯虚数，可得202a -=且202a+≠，解得2a =， 所以实数a 等于2. 故选：B. 【点睛】本题主要考查了复数的除法运算，以及复数的基本概念的应用，其中解答中熟记复数的运算法则，结合复数的基本概念求解是解答的关键，着重考查推理与运算能力.12．A解析：A 【分析】根据条件可得042z i -<，即复数0z 对应的点在以()0,4为圆心，2为半径的圆内部.01z -表示复数0z 对应的点到()1,0的距离，由圆的性质可得答案.【详解】因为042z i z z -+-=的复数z 对应的点的轨迹是椭圆， 所以042z i -<由复数的几何意义可知042z i -<表示复数0z 对应的点到()0,4的距离小于2. 即复数0z 对应的点在以()0,4为圆心，2为半径的圆内部.01z -表示复数0z 对应的点到()1,0的距离.如图，设()0,4C ,1,0A 221417AC =+=则0212AC z AC -<-<+,即01721172z -<-<+ 故选：A【点睛】本题考查椭圆的定义的应用，考查复数的几何意义的应用和利用圆的性质求范围，属于中档题.二、填空题13．1【分析】复数满足为虚数单位）设利用复数模的计算公式与三角函数求值即可得出【详解】解：复数满足为虚数单位）设则当且仅当时取等号故答案为：1【点睛】本题考查了复数的运算法则模的计算公式及其三角函数求值解析：1 【分析】复数z 满足||1(z i =为虚数单位），设cos sin z i θθ=+，[0θ∈，2)π．利用复数模的计算公式与三角函数求值即可得出． 【详解】 解：复数z 满足||1(z i =为虚数单位）， 设cos sin z i θθ=+，[0θ∈，2)π． 则22|2||cos (sin 2)|(sin 2)54sin 1z i i cos θθθθθ-=+-+--，当且仅当sin 1θ=时取等号． 故答案为：1． 【点睛】本题考查了复数的运算法则、模的计算公式及其三角函数求值，考查了推理能力与计算能力，属于中档题．14．【分析】先化简再解方程即得解【详解】由题得因为复数的实部和虚部互为相反数所以故答案为：【点睛】本题主要考查复数的除法运算考查复数实部虚部的概念意在考查学生对这些知识的理解掌握水平解析：23-【分析】先化简222(4)125bi b b i i ---+=+，再解方程224+055b b---=即得解. 【详解】由题得2(2)(12)22(4)12(12)(12)5bi bi i b b ii i i -----+==++-， 因为复数212bii -+的实部和虚部互为相反数， 所以2242+0,553b b b ---=∴=-. 故答案为：23-【点睛】本题主要考查复数的除法运算，考查复数实部虚部的概念，意在考查学生对这些知识的理解掌握水平.15．【分析】设利用列方程组解方程组求得题目所求两个数【详解】设依题意有即所以将代入得；将代入解得；将代入得结合解得或所以对应的数为故答案为：【点睛】本小题主要考查复数运算属于中档题 解析：2i ±【分析】设()12,,,,z a bi z c di a b c d R =+=+∈，利用12124,5z z z z +=⋅=列方程组，解方程组求得题目所求两个数. 【详解】设()12,,,,z a bi z c di a b c d R =+=+∈，依题意有12124,5z z z z +=⋅=，即()()45a c b d i ac bd ad bc i ⎧+++=⎪⎨-++=⎪⎩，所以405a cb d ac bd ad bc +=⎧⎪+=⎪⎨-=⎪⎪+=⎩.将=-b d 代入0ad bc +=，得a c =；将a c =代入4a c +=，解得2a c ==；将2a c ==代入5ac bd -=，得1bd =-，结合=-b d 解得11b d =⎧⎨=-⎩或11b d =-⎧⎨=⎩.所以对应的数为2i +、2i -. 故答案为：2i ± 【点睛】本小题主要考查复数运算，属于中档题.16．【分析】确定复数对应点在第一象限旋转后在轴的正半轴上计算复数模得到答案【详解】对应的点为在第一象限逆时针旋转最小正角时对应的点在轴的正半轴上故纯虚数为故答案为：【点睛】本题考查了复数对应的点复数的旋 解析：5i【分析】确定复数对应点在第一象限，旋转后在y 轴的正半轴上，计算复数模得到答案. 【详解】34z i =+，对应的点为()3,4在第一象限，逆时针旋转最小正角时，对应的点在y 轴的正半轴上，22345z =+=，故纯虚数为5i . 故答案为：5i . 【点睛】本题考查了复数对应的点，复数的旋转，意在考查学生的计算能力和综合应用能力.17．π【分析】先把复数分母有理化再根据z 在第四象限和|z|≤2可得关于xy 的不等式组进而可得点P 在平面上形成的区域面积【详解】由题得z=x+yi1+i=x+y+(y-x)i2z 在第四象限则有x+y2>0 解析：【分析】先把复数分母有理化，再根据z 在第四象限和，可得关于x ，y 的不等式组，进而可得点P 在平面上形成的区域面积． 【详解】由题得，z 在第四象限，则有，整理得，由得，化简得，则点在不等式组所表示的平面区域内，如图阴影部分：则其面积.【点睛】本题考查复数的运算和复数的模，与线性规划相结合，有一定综合性．18．【分析】由题意画出图形数形结合得答案【详解】|z ﹣1﹣i|＝1的几何意义为复平面内动点到定点（11）距离为1的点的轨迹如图：|z ﹣3|可以看作圆上的点到点(30)的距离由图可知|z ﹣3|的最大值为故 解析：51+【分析】由题意画出图形，数形结合得答案． 【详解】|z ﹣1﹣i |＝1的几何意义为复平面内动点到定点（1，1）距离为1的点的轨迹， 如图：|z ﹣3|可以看作圆上的点到点(3,0)的距离.由图可知，|z ﹣3|22(31)(01)151-+-=． 51． 【点睛】本题考查复数模的求法，考查数形结合的解题思想方法，是基础题．19．【分析】先根据复数除法得再根据共轭复数概念得【详解】因为所以即【点睛】本题重点考查复数的概念与复数相等属于基本题复数的实部为虚部为模为对应点为共轭为 解析：2i +【分析】先根据复数除法得z ，再根据共轭复数概念得z . 【详解】因为()1243i z i +=+，所以43212iz i i+==-+,即2.z i =+ 【点睛】本题重点考查复数的概念与复数相等，属于基本题.复数(,)a bi a b R +∈的实部为a 、虚部为b 22a b +(,)a b 、共轭为.-a bi20．3i 【解析】设z=a+bi(ab ∈R)因为|z|=3所以a2+b2=9又z+3i=a+bi+3i=a+(b+3)i 为纯虚数所以即又a2+b2=9所以a=0b=3所以z=3i解析：3i【解析】设z=a+bi(a,b ∈R),因为|z|=3,所以a 2+b 2=9.又z+3i=a+bi+3i=a+(b+3)i 为纯虚数,所以a 0,b 30,=⎧⎨+≠⎩即a 0,b 3.=⎧⎨≠-⎩ 又a 2+b 2=9,所以a=0,b=3,所以z=3i.三、解答题21．（1）123626z z i ⋅=--；（2）1或4. 【分析】 （1）由复数12z z z =-为纯虚数，可得2220230a a a a ⎧--=⎨--≠⎩，从而可求出a 的值，进而可求出12z z ⋅的值；（2）由1z z i +=-，可得复数z 在直线y x =-上，所以22232a a a a --=-++，从而可求出a 的值，进而可得z i +的值【详解】解：（1）()()22122241()z z a a a a i a R -=--+--++∈为纯虚数， ∴2220230a a a a ⎧--=⎨--≠⎩，解得2a =， ∴128z i =-，225z i =-，∴12(28)(25)3626z z i i i ⋅=-⋅-=--.（2）()()2212223z z z a a a a i =-=--+--， ∵1z z i +=-，∴复数z 对应的点22(2,23)a a a a ----在直线y x =-上，即22232a a a a --=-++，解得1a =-或52a =. 当1a =-时，0z =，1z i +=；当52a =时，7744z i =-，7344z i i +=-=. 【点睛】此题考查复数的有关概念，考查复数的模，考查计算能力，属于中档题22．（1）12z =；（2）13a > 【分析】 (1)先根据条件得到13z i =-，进而得到15122z i =--，由复数的模的求法得到结果；（2）由第一问得到2(3)(31)10a a i z ++-=，根据复数对应的点在第一象限得到不等式30310a a +>⎧⎨->⎩，进而求解. 【详解】∵1z mi =+，∴1z mi =-.∴(3)(1)(3)(3)(13)z i mi i m m i ⋅+=-+=++-.又∵(3)z i ⋅+为纯虚数，∴30130m m +=⎧⎨-≠⎩，解得3m =-．∴13z i =-.（1）13251122i z i i -+==---，∴1z = （2）∵13z i =-，∴2(3)(31)1310a i a a i z i -++-==-， 又∵复数2z 所对应的点在第一象限，∴30310a a +>⎧⎨->⎩，解得：13a >． 【点睛】如果Z 是复平面内表示复数z a bi =+(),a b ∈R 的点，则①当0a >，0b >时，点Z 位于第一象限；当0a <，0b >时，点Z 位于第二象限；当0a <，0b <时，点Z 位于第三象限；当0a >，0b <时，点Z 位于第四象限;②当0b >时，点Z 位于实轴上方的半平面内；当0b <时，点Z 位于实轴下方的半平面内．23．（1）5m =或3-；（2）2m =-；（3）12m =或2- 【分析】复数222(1)(52)(615)(56)(215)z i m i m i m m m m i =++-+-=+++--．（1）由22150m m --=，解得m 即可得出． （2）由225602150m m m m ⎧++=⎨--≠⎩，解得m 即可得出． （3）由22(56)(215)70m m m m +++--+=．解出即可得出．【详解】解：复数222(1)(52)(615)(56)(215)z i m i m i m m m m i =++-+-=+++--．（1）由22150m m --=，解得5m =或3-．5m ∴=或3-时，复数z 为实数．（2）由225602150m m m m ⎧++=⎨--≠⎩，解得2m =-． 2m ∴=-时，复数z 为纯虚数．（3）由22(56)(215)70m m m m +++--+=．化为：22320m m +-=， 解得12m =或2-． 12m ∴=或2-，z 对应点在直线70x y ++=上． 【点睛】本题考查了复数的运算法则及其有关概念，考查了推理能力与计算能力，属于中档题． 24．3【分析】根据|22|1z i +-=，结合复数减法的模的几何意义，判断出z 对应点的轨迹，再根据复数减法的模的几何意义，结合圆的几何性质，求得|22|z i --的最小值.【详解】由|22|1z i +-=得|(22)|1z i --+=，因此复数z 对应的点Z 在以022z i =-+对应的点0Z 为圆心，1为半径的圆上，如图所示.设|22|y z i =--，则y 是Z 点到22i +对应的点A 的距离.又04AZ =，∴由图知min 0||13y AZ =-=.【点睛】 本小题主要考查复数减法的模的几何意义，考查数形结合的数学思想方法，属于基础题. 25．（1）22z i =+或22z i =-；（2）()0,4.【分析】（1）由于z 为虚数，可设(z x yi x =+，y R ∈，0)y ≠，根据2z -为纯虚数，求得x 的值，再由42z z +-为实数求出y 的值，即得虚数z ； （2）由42z z +-为实数且0y ≠，可得22(2)4x y -+=，根据2204(2)y x =-->，求得x 的范围，根据复数的模的定义，化简为4164z x -=-164x -的范围，即可得出|4|z -的取值范围．【详解】解：由于z 为虚数，可设(z x yi x =+，y R ∈，0)y ≠，（1）则22z x yi -=-+，由2z -为纯虚数，得2x =，2z yi ∴=+， 又因为42z z +-为实数， 则(442)242z yi y i R z yi y +=++=+-∈-， 得40y y-=，2y =±， 所以22z i =+或22z i =-. （2）2222(4442)4[]22(2)(2)x y z x yi x y i R z x yi x y x y -+=++=++-∈-+--+-+， 因为42z z +-为实数， ∴2240(2)y y x y -=-+， 0y ≠，22(2)4x y ∴-+=，224(2)0y x =-->∴，则2(2)4x -<，解得：(0,4)x ∈，∴|4||4|z x yi -=+-由于(0,4)x ∈，则016416x <-<，所以04<<，即0|4|4z <-<，所以|4|z -的取值范围为()0,4.【点睛】本题考查复数的基本概念，两个复数代数形式的除法以及复数求模，考查运算求解能力．26．（1）31a b =⎧⎨=⎩或232a b =⎧⎪⎨=⎪⎩;（2）见解析. 【分析】（1）由复数的乘法可得()22z a b ab i =+--，由5z i =-可知2521a b ab +=⎧⎨-=⎩，从而可求出a ，b 的值；（2）由z 的实部为2可得22a b +=，结合“1”的代换可知211442a b a b b a ⎛⎫+=++ ⎪⎝⎭，由基本不等式可证明214a b+≥. 【详解】 （1）解：由()()()21225z a i bi a b ab i i =+-=+--=-，则2521a b ab +=⎧⎨-=⎩ ， 解得31a b =⎧⎨=⎩或232a b =⎧⎪⎨=⎪⎩（2）证明：由题意知，22a b +=，所以()21121142422a b a b a b a b b a ⎛⎫⎛⎫+=++=++ ⎪ ⎪⎝⎭⎝⎭， 因为0a >，0b >，所以44a b b a +≥=， 当且仅当4a b b a =，即11,2a b == 时等号成立，则()2114442a b +≥⨯+=. 【点睛】本题考查了复数的乘法运算，考查了基本不等式，考查了复数的定义.运用基本不等式求最值时，注意一正二定三相等.。
(人教版2017课标)高中英语必修第一册 Unit 2单元测试02-含答案
Unit 2 Travelling Around 单元测试一、听力（共两节，满分30分）第一节（共5小题；每小题1.5分，满分7.5分）听下面5段对话。
每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。
听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. What’s John’s address?A. 1434 King Street.B. 1344 Queen Street.C. 1343 King Street.2. How old is the woman’s car?A. One week old.B. One month old.C. Three years old.3. How much does the skirt cost?A. $ 6.B. $ 12.C. $ 24.4. What’s the weather like these days?A. Cold.B. Agreeable.C. Hot.5. How will the woman go to New York?A. By airplane.B. By train.C. By car.第二节（共15小题；每小题1.5分，满分22.5分）听下面5段对话或独白。
每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。
听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。
每段对话或独白读两遍。
听第6段材料，回答第6、7题。
6. What will there be after class?A. A meeting.B. A new film.C. A sports meeting7. Why can’t the woman come?A. She has to visit Bob.B. She has to do her homework.C. She has to look after her mother.听第7段材料，回答第8、9题。
人教版高中英语必修第二册unit2复习课件
02
语法
Present continuous passive voice
Unit 2
Wildlife Protection
单词
01
语言点
02
目录
语法
03
课文
04
01
单词
● 1.illegal adj.不合法的；非法的→legal adj.合法的→illegally adv.不 合法地；非法地 3.alarm vt.使惊恐；使害怕；使担心n.恐慌；警报；警报器→alarming adj.惊人的；使人惊恐的
现在进行时被动语态
Revision of the Passive Voice
5. WWF hopes that more and more wild animals
w__il_l_b_e_p__ro_t_e_c_t_ed_ (protect) in the future. 将来时被动语态
6. Lily just told me Jack _h_a_d_b_e_e_n__f_ir_e_d(fire) since last
Revision of the Passive Voice
1. Every year over 29,000 antelopes _a_r_e_k_i_ll_e_d (kill) in Tibet.
一般现在时被动语态 2. In the past, the elephants _w_e_r_e_k__il_le_d_ (kill) by farmers.
外研版)高中英语必修第二册Unit2单元测试试卷(含答案)03
加油！有志者事竟成答卷时应注意事项１、拿到试卷，要认真仔细的先填好自己的考生信息。
２、拿到试卷不要提笔就写，先大致的浏览一遍，有多少大题，每个大题里有几个小题，有什么题型，哪些容易，哪些难，做到心里有底；３、审题，每个题目都要多读几遍，不仅要读大题，还要读小题，不放过每一个字，遇到暂时弄不懂题意的题目，手指点读，多读几遍题目，就能理解题意了；容易混乱的地方也应该多读几遍，比如从小到大，从左到右这样的题；４、每个题目做完了以后，把自己的手从试卷上完全移开，好好的看看有没有被自己的手臂挡住而遗漏的题；试卷第１页和第２页上下衔接的地方一定要注意，仔细看看有没有遗漏的小题；５、中途遇到真的解决不了的难题，注意安排好时间，先把后面会做的做完，再来重新读题，结合平时课堂上所学的知识，解答难题；一定要镇定，不能因此慌了手脚，影响下面的答题；６、卷面要清洁，字迹要清工整，非常重要；７、做完的试卷要检查，这样可以发现刚才可能留下的错误或是可以检查是否有漏题，检查的时候，用手指点读题目，不要管自己的答案，重新分析题意，所有计算题重新计算，判断题重新判断，填空题重新填空，之后把检查的结果与先前做的结果进行对比分析。
亲爱的小朋友，你们好! 经过两个月的学习，你们一定有不小的收获吧，用你的自信和智慧，认真答题，相信你一定会闯关成功。
相信你是最棒的！单元测试一、根据汉语提示写出正确的单词（每小题0.5分，共5分）1. What does the ________ （龙）represent in Western culture?2. Mike and Peter are of the same ________ （国籍）.3. Grandpa made a ________ （灯笼）out of a pumpkin, and the kids all like it very much.4. Mr Smith opened the ________ （信封）and took out a letter.5. We’ve fixed the date for the outing and we’ll go ________ （不管，不顾）of wind or rain.6. Dickens’ novels have enriched English ________ （文学）.7. Our vote today ________ （显示）a change in our country’s political policy.8. Will the ________ （软件）run on my computer?9. Without an ________ （观众）the performance is pointless.10. Will you ________ （向……表示敬意）me with a visit?二、用所给单词的正确形式填空（每小题0.5分，共5分）1. Colourful paper ________ （decorate）have been hung from the ceiling.2. Gender ________ （equality）is still a problem in some regions.3. Just now, he ________ （admit）that he might be a little bit nervous on the stage.4. Construction also continues to be a strong sector ________ （global）.5. Mrs Palmer is a ________ （retire）maths teacher.6. Bob Green began his career as a sound ________ （edit）.7. His death is a great ________ （lose）to his country.8. Most people don’t believe in the ________ （exist）of ghosts.9. A career in law is becoming increasingly ________ （attract）to young people.10. I really like ________ （formal）English, and it’s more casual than formal English.三、选择合适的短语，并用其正确形式，完成句子（每小题1分，共5分）1. I enjoy going with my friends to ________.2. John Brown is ________ the best doctor in town.3. ________ we are united, there is no difficulty we cannot overcome.4. My elder brother ________ pop music since he entered high school.5. What did this ________ my daughter’s wedding?四、阅读理解（每小题2分，共30分）阅读下列短文，从每题所给的A、B、C和D四个选项中，选出最佳选项。
高中英语人教版精品课件《人民教育出版社（人教版2017课标）高中英语必修 第二册Revision 2》
The report is being written by one of the best students 报告正由一名最优秀的学生写着呢。 The report is well written系表结构 这个报告写得很好。 2现在进行时的被动语态也可以表示将来。 现在进行时的被动语态有时可表示按计划或安排将要进行的一个被 动动作此种用法仅限于少数及物动词，如：hold，tae等。 A party is being held tonight今晚将要举行一场晚会。
【句式解读】 句中Only whencan we stop是“only＋状语”位于句首的倒装句式。 【用法总结】“only＋状语”位于句首的倒装句式有以下几种情形： 1“only＋副词”位于句首 ①Only then did I realie that I was wrong只是那时我才意识到是我错了。
3现在进行时的被动语态注意要点 1不可遗漏being。 现在进行时的被动语态表示说话时正在进行的一个被动的动作，如 果我们把being漏掉，即成为一般现在时的被动语态或系表结构。 Loo！The children are being taen care of by their aunt 瞧！那些孩子正由他们的姑妈照看着。
Grammar
02
1现在进行时的被动语态的构成形式
形式
结构
肯定形式 主语＋be (am，is，are)＋being＋vt. P.P
否定形式 主语＋be (am，is，are)＋not＋being＋vt. P.P
一般疑问式 Be (am，is，are)＋主语＋being＋vt. P.P
人教版高中英语选择性必修第二册精品课件 Unit 2 Section Ⅱ
【合作探究】
读一读·细观察
阅读下列句子,写出句中黑体词的词性和含义
①How do you motivate people to work hard and efficiently?
词性 动词
含义 激发;激励
②We usually have more pleasure and motivation to work on
答案:We learnt from his letter that he was in Spain.(宾语从
句)
5.The truth is that it is too foggy for the bus to run that far.
( )
答案:The truth is that it is too foggy for the bus to run that
motivate
/̍məʊtIveIt/vt.成为……的动机;激发;激励
expectation
/̩ekspek̍teIʃn/n.期望;预期;期待
culture shock
文化冲击
departure
/dI̍pɑːtʃə(r)/n.离开;启程;出发
exposure
/Ik̍spəʊʒə(r)/n.接触;体验;暴露;揭露→
3. overwhelming /̩əʊvə̍welmI /adj.无法抗拒的;巨大的;
压倒性的
homesickness
4.
/̍həʊmsIknəs/nຫໍສະໝຸດ 思乡病;乡愁5.→
→
6.
7.
8.
9.
境)
motivated /̍məʊtIveItId/adj.积极的;主动的
motivation /̩məʊtI̍veIʃn/n.动力;积极性;动机
高中英语(新人教版)必修第二册课后习题：UNIT 2 Section C(课后习题)【含答案及解析】
UNIT2WILDLIFE PROTECTION Section C Discovering Useful Structures&Listening and Talking课后篇巩固提升必备知识基础练Ⅰ.选词填空1.A man dead in the city centre last night.2.Some species in this small area of forest and nowhere else on Earth.3.Once the damage is done,it will take many years for the farmland.4.His house had clearly been and the book was missing.5.The traveller may fire at a wild beast to defend himself in case he.6.Though having lived abroad for years,many Chinese still the traditional customs.7.The new traffic law is mainly to lower the rate of traffic accidents and injuries.8.The new bridge should travelling time from 50 minutes to 15 minutes.Ⅱ.完成句子1.他的失败是由于他没有练习很长时间。
His failure was the fact that he had not practised for a long time.2.狗的嗅觉非常灵敏,经常被用来寻找地震中的幸存者。
Dogs have a very good sense of smell and are often used survivors in an earthquake.3.我们的政府正采取措施防止和控制污染。