鄭州四中2008~2009學(xué)年上學(xué)期高二年級期中考試
英語試卷 命題人：彭佩霞
注意事項：
1.本試卷分為第一卷和第二卷，共5頁，第一卷1-4頁，第二卷第5頁；考試時間為100分鐘；卷面分120分。
2.第一卷的答案用鉛筆涂在答題卡上，第二卷用鋼筆或圓珠筆寫在指定的位置上；不按要求做題不給分。
3.交卷時，只交答題卡和第二卷。
第一卷
Ⅰ 單項填空（共15小題；每小題1分，滿分15分）
1. I try to ______ a few minutes every day to do some exercises.
A. set out B. set off C. set up D. set aside
2. The sound of happy laughter ______ memories of his childhood.
A. called for B. called on C. called at D. called up
3. It is the prevention of disease ______its successful treatments that has led to the rapid increase of the world’s population.
A. other than B. rather than C. less than D. but also
4. Being determined is a kind of quality and that’s______ it takes to do anything properly.
A. how B. which C. where D. what
5.The reason ______I have to go is ______my mother is ill in bed.
A. why ;why B. why; because
C. why ;that D. that ;because
6. The earth moves around the sun, not______.
A. the other way back B. another way round
C. the other way around D. another way against
7.
A. inspiring to B. inspired to
C. inspired by D. inspiring by
8. Engines are to machines______ hearts are to animals.
A. that B. what
C. where D. which
9. ______we must do is ______the use of energy.
A. That; to reduce B. How; to reduce
C .What; to reduce D. That; reduce
10. ______ by the beauty of nature, the girl
from
A. Attracting B. Attracted
C. To be attracted D. Having attracted
11. Many things ______impossible for Chinese to understand in the past are quite common today.
A. considering B. considered
C. to be considered D .having been considered
12. To know what is good and ______are two different things.
A. doing what is right B. does what is right
C. to do what is right D. did what was right
13. The joke made by Tom made us ______,so the teacher couldn’t make himself______.
A. to laugh; hearing B .laugh; heard
C. laughing; hear D. laughed; heard
14. Her French upbringing gives her certain advantages ______other students in her class.
A. on B. up to C. over D. more than
15.―Do you think living in the county has advantages?
― .
A. Yes, perfectly B. Yes, it is
C. Nothing at all D. Well, that depends
II. 完型填空（共20小題，每小題1.5分，滿分30分）
If you have strong arms and feet, you might make a good waiter. You must 16 , however, not in the restaurant, but in the 17 , helping the head cook, to learn exactly 18 each dish is prepared. Then you will be able to tell the customers what the ingredients (成分)are and how the food is 19 .From this first step, you may enter the restaurant as a 20 . But you won’t be allowed to serve the customers yet. They will 21 let you do the simplest jobs, such as 22 the tables and carrying the plates. But all the time you must watch and learn. Later you will be taught how to 23 food and if you are good at it, you may become a waiter in charge of a number of 24 .You may even become a head waiter 25 you are afraid of hard work.
When
Carlo Bianchi first arrived in London, he 26
only two English words ― “Please” and “ Hello ”. He 27 to get a job helping in the kitchen of an
Indian restaurant, and he spent 28 little spare time he had learning
English. He was a good worker and soon he got a job in the restaurant as a
waiter. Every night, Carlo used to go home tired, but 29
too tired to study the language for half an hour before going to
sleep. He always managed to
16. A. work B. start C. cook D. learn
17. A. market B. school C. workshop D. kitchen
18. A. when B. how C. what D. where
19. A. served B. eaten C. cooked D. bought
20. A. learner B. waiter C. cook D. observer
21. A. soon B. only C. later D. hardly
22. A. laying B. lying C. putting D. moving
23. A. take B. make C. carry D. serve
24. A. tables B. waiters C. foods D. jobs
25. A. if B. before C. unless D. though
26. A. spoke B. studied C. heard D. kept in mind
27. A. failed B. tried C. managed D. intended
28. A. how B. what C. such D. that
29. A. only B. sometimes C. little D. never
30. A. spare B. leave C. save D. get
31. A. as B. leave C. those D. which
32. A. friendship B. dish C. welcome D. smile
33. A. and B. for C. even D. therefore
34. A. again B. late C. lately D. more
35. A. opinion B. touch C. effort D. effect
III．閱讀理解(共20小題，每小題2分，滿分40分)
閱讀下列短文，從每題所給的四個選項(A、B、C、D)中選出最佳選項。
A
Some people are lucky enough to be born with a good sense of direction and even if they have only visited a place once, they will be able to find it again years later.
I am one of those unfortunate people who have poor sense of direction and I may have visited a place time after time but I still get lost on my way there. When I was young I was so shy that I never dared ask complete strangers the way and so I used to wander round in circles and hope that by some chance I would get to the spot I was heading for.
I am no longer too shy to ask people for direction, but I often receive replies that puzzle me. Often people do not like to admit that they didn’t know their hometown and will insist on telling you the way, even if they do not know it; others, who are anxious to prove that they know their hometown very well, will give you a long list of directions which you can not possibly hope to remember, and still others do not seem to be able to tell between their left and their right and you find in the end that you are going in the opposite direction to that in which you should be going.
If anyone ever asks me the way to somewhere, I always tell them I am a stranger to the town in order to avoid giving them wrong direction but even this can have embarrassing results.
Once I was on my way to
work when I was stopped by a man who asked me if I would direct him the way to
the
Imagine my embarrassment when my secretary showed in the very man who had asked for directions to my office and his astonishment when he recognized me as the person he had asked.
36.What is the writer going to do when someone asks him for direction?
A. He will direct the right way to the person willingly.
B. He will reply to it by means of being a stranger to the town.
C. He will give the very person long list of direction.
D. He is going to show the man an opposite direction.
37.Why did the writer consider himself to be an unlucky dog?
A. Because of his poor sense of direction.
B. Because he always forget the way to home.
C. Because he did not have any friend.
D. Because he used to be shy and dared not ask others the way.
38.How did the visitor feel when he was showed into the very room?
A. He felt strange. B. He felt embarrassed.
C. He felt very sad. D. He felt astonished.
39.Who showed the right way to the interviewee according to the passage?
A. Someone we don’t know.
B. The writer did it for himself.
C. The secretary did so.
D. A warm-hearted old lady did such a thing.
B
Suppose you want to buy some new clothes or a new TV. Or maybe you need some work done on your car. How can you find the best price without shopping all over town? Ads can help you. Ads can show you lots of prices. And you don’t have to go anywhere to see them. Just open a newspaper or magazine, and you’ll find plenty of ads.
The following is an ad about TV sets for sale. Please read it and answer the questions below.
40.How many different kinds of TV sets does the store advertise here?
A. Four. B. Three. C. Two. D. Five.
41.Which of the following statements is TRUE according to the advertisement?
A. You can buy any kind on July 14th.
B. The service time is 9 to 9 every day except Monday.
C. The larger the screen is, the higher the price will be.
D. The lowest price is a little more than 300.
42.Which is NOT mentioned in the ad?
A. The date of the American National Day.
B. The post code of the area where the store is.
C. The phone number of the store.
D. The names of the TV sets.
C
Celebrations spread across
Shanghai won the honor
after beating rivals from Russia, Mexico,
“I’m very proud of being Chinese,”said Wang Kaibo, a Senior 2 student of the Middle School Affiliated to Beijing Medical University.“The winning of the expo is a victory, not only for Shanghai residents, but for the people of the whole Chinese nation.”
Bidding for the expo shows
that
The World Expo 2010 and
the 2008
The World Expo is known as “Olympics of the economic, cultural, scientific and technological fields.”It is usually held every five years and lasts for six months.
The Olympics, World Cup and World Expo are considered three top international events in the world.
Not only will it attract
more foreign investment to
The World Expo is a great event for different countries to exchange social, economic, cultural and scientific achievements, and also help to encourage new technology and ideas.
The expo was first held in
The
Many historic inventions, such as the telephone and airplane, all made their first appearance at a World Expo.
43.What does the underlined word “rivals” probably mean in the second paragraph?
A. Competitors. B. Enemies.
C. Players. D. Supporters.
44.The winning of bidding for the World Expo 2010 and the 2008 Olympic Games implies______.
A. China is beginning to play a more important part on the international stage
B. China has played the most important role in the international affairs
C. China has become a developed country ever since 53
D.
45.As we know, in general, the World Expo is usually held every ______years, while the Olympics is usually held every ______ years.
A.4;5 B.5;
46.By bidding for the expo and the Olympics, we are sure that______.
A. China will beat rivals from Russia, Mexico, Poland and South Korea
B. China will become a super country in the United Nations
C. China will build a famous tower like Eiffel Tower as the symbol of the capital
D. China will develop more quickly than before and will benefit a lot from them
D
If you go into the forest with your friends, stay with them. If you don’t, you’ll get lost. If you get lost, this is what you should do. Sit down and stay where you are. Don’t try to find your friends―Let them find you .You can help them find you are staying in one place. There is another way to help your friends or other people to find you. You can shout or whistle（吹口哨）three times. Stop. Then shout or whistle three times again. Any signal(信號)given three times is a call for help.
Keep up shouting or whistling. Always three times together. When people hear you, they will know that you are not just making a noise for fun. They will let you know that they have heard your signal. They will give you two shouts or two whistles. When a signal is given twice, it is an answer to a call for help.
If you don’t think that you will get help before night comes, try to make a little house with branches(樹枝).Make yourself a bed with leaves and grass.
When away, Pick off small branches and drop them as walking in order to go back again easily. When you are lost, the most important thing to do is to stay in one place.
47. If you get lost in the forest, you should______.
A. try to find your friends B. stay in one place and give signs
C. walk around the forest D. shout as loudly as possible
48. Which signal is a call for help?
A. Shouting here and there. B. Crying twice.
C. Shouting or whistling three times together D. Whistling everything in the forest
49. When you hear two shouts or two whistles, you know that___.
A. someone is afraid of an anima B. people will come to help
C. someone needs help D. something terrible will happen
50. The main idea of the passage is _____________.
A. how to travel in the forest
B. how to spend the night in the forest
C. what you should do if you want to get some water
D. what you should do if you are lost in the forest
E
A new study shows that fat people in the United States suffer direct economic(經(jīng)濟的) and social effects because of their size. The findings are from an 8-year study of about 100 000 people. The people studied were between the ages of 16 and 24 when the research began.
The researchers who carried out the study say they consider the people fat if they are in the top of 5% of the measurement in which weight is connected with height. For example, fat women in the study were about 160 centimeters tall and weighed about 90 kilograms. Fat men in the study were about 175 centimeters tall and weighed 100 kilograms. The researchers say that more than 1 000 000 Americans are that big. The researchers found that fat young women were more likely to lose social and economic power even if they were form wealthy families. The fat women also were 20% less likely to get married and they earned an average of about $6 700 a year less than other women. The study showed less severe effect on fat men. They earned an average of about $3 000 a year less than other men. Fat men also were 11% less likely to get married.
51.From this passage we know fat people in America were______.
A. admired B. respected
C. unhealthy D. unpopular
52.Which of the following is surely RIGHT?
A. If a woman weighed 90 kilograms, she was considered fat.
B. More than 1 000 000 Americans were about 175 centimeters tall and weighed 100 kilograms.
C. More than 1 000 000 Americans were considered fat by the researchers.
D. In America 20% of women and 11% of men couldn’t get married.
53.Which of the following was NOT mentioned in this passage?
A. The reason why fat people suffered.
B. The cause that caused people to be fat.
C. The standard(標(biāo)準(zhǔn)) of fat people.
D. The number of fat people.
54.The underlined word “severe” means______.
A. economic B. social
C. serious D. favourable
55.Fat people were inferior to(比……差) other people in______.
A. brains, human rights and payment
B. income, marriage and political rights
C. brains ,education and marriage
D. marriage, getting jobs and income
第Ⅱ卷(共35分)
(共兩節(jié)，滿分35分)
第一節(jié)：短文改錯(共10小題，每小題1分, 滿分10分)
此題要求改正所給短文中的錯誤。對標(biāo)有題號的每一行作出判斷。如無錯誤，在該行右邊橫線上劃一個勾(√)；如有錯誤(每行只有一個錯誤)，則按下列情況改正：
該行多一個詞：把多余的詞用斜線(＼)劃掉，在該行右邊橫線上寫出該詞，并也用斜線劃掉。
該行缺一個詞：在缺詞處加一個漏字符號(∧)，在該行右邊橫線上寫出該加的詞。
該行錯一個詞：在錯的詞下劃一橫線，在該行右邊橫線上寫出改正后的詞。
注意：原行沒有錯的不要改。
After read your advertisement, I want to offer 56.___________
myself for the position. I’m twenty years old, male, 57. ___________
1.78 meters tall, strong and health. And I am going to 58. ___________
graduate Nanjing University this year. I have learned 59. ___________
English for ten years. My spoken English is very much 60. ___________
good and I can write good article. I have won several 61. ___________
prizes in English contests. I have made a great deal of 62. ___________
inventions, most of them have been put into practice. 63. ___________
But I can use the computer skillfully. 64. ___________
If I can get the job, I’ll do all I can do it well． 65.___________
Thank you for your kindness.
Yours truly,
Li Hua
第二節(jié)：書面表達（共25 分）
根據(jù)下列圖畫用英語寫一篇短文，圖中男子為Mr. Li。
參考詞匯：
足球迷 a football fan
• Mrs. Li 讓Mr. Li照看廚房的飯；
• Mr. Li完全沉迷于球賽；
• Mrs. Li 回來聞到了糊味；
• 看到飯糊了，Mr. Li 這時才意識到自己的任務(wù)。
注意：1．短文應(yīng)包括圖中所提供的主要信息，井做適當(dāng)發(fā)揮，使短文內(nèi)容連貫、完整；
2．詞數(shù)： 100左右．
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鄭州四中高二英語期中考試答案
I 單項選擇
1---5 DDBDC 6―10 CCBCB 11---15 BCBCD
II 完型填空
Ⅲ. 16－20 BDBCA； 21－25 BADAC ；26－30 ACBDC；
31－35 DDACB
IV. 閱讀理解
36 －40 BADAD 41-45 CBAAB 46---50 DBCBD
51―55 DCBCD
V. 短文改錯
56. read→reading 57. √ 58. health→healthy 59. graduate后加from 60. 去掉much 61. article→articles 62. deal→number 63. them→which 64. But→And 65. 第二個do前加to
VI. 書面表達
Mr. Li is a football fan. One day, his wife wanted to go shopping and asked his husband to keep an eye on the meal being cooked in the kitchen. Mr. Li said, “No problem.” After his wife left, he began to watch TV, a football match. It was very exciting. Mr. Li lost himself in the match at once, forgetting the meal completely. When his wife came home, she felt something smelt terrible. She rushed into the kitchen and found the dish had been burnt black. Only at that moment did Mr. Li realize his task.(93 words)
2008年武漢市實驗學(xué)校高一理科實驗班12月考試物理試卷
1．如圖所示，水平推力
使重為
的物體靜止在豎直墻壁上，若物體與墻間的動摩擦因數(shù)為
，則物體與墻壁間的摩擦力的大小為
A． B． C．
D．
2．甲、乙兩物體質(zhì)量之比
，速度之比
，在相同的阻力作用下逐漸停止，則它們通過的位移
是
A．1:1 B．1:
3．利用傳感器和計算機可以測量快速變化的力，如圖是用這種方法獲得彈性繩中拉力隨時間
變化的關(guān)系圖線。實驗時，把小球舉高到繩子的懸點
處，然后讓其自由下落，根據(jù)圖線所提供的信息可判定下面說法正確的是
A．
時刻小球速度最大
B．
時刻繩子最長
C．
時刻小球合力最大
D．與
時刻小球加速度相同
4．如圖所示，一質(zhì)量為
的木塊與水平面接觸，木塊上方固定有一根直立的輕彈簧，彈上端系一質(zhì)量為
的小球，小球可在豎直方向上來回運動。在該裝置的上方存在著一個無上邊界的特殊區(qū)域，該區(qū)域具有這樣的性質(zhì)：只要小球在該區(qū)域里時小球就會受到一個恒定的向上的力的作用。經(jīng)試驗發(fā)現(xiàn)：當(dāng)小球向上運動剛好到達該區(qū)域里時彈簧正好為原長，且小球恰好具有最大速度。則當(dāng)木塊對水平面壓力恰好為零時，小球的加速度大小是
A．
B．
C．
D．
5．在光滑的水平面上有一個物體同時受到兩個水平力
和
的作用，在第1s內(nèi)保持靜止?fàn)顟B(tài)。若兩個力隨時間變化的情況如圖所示，則下列說法正確的是
A．在第2s內(nèi)物體做勻加速運動，加速度大小恒定，速度均勻增大
B．在第5s內(nèi)物體做變加速運動，加速度均勻減小，速度逐漸增大
C．在第3s內(nèi)物體做變加速運動，加速度均勻減小，速度均勻減小
D．在第6s末，物體的加速度和速度均為零
6．如圖所示，A、B兩個物體放于光滑水平面上，對A物體施加
的拉力，對B物體懸掛重物為
的物體，若滑輪摩擦不計，則A、B兩個物體的加速度的大小分別為
和
，則下面說法正確的是
A．
B．
C．
D．無法判斷
7．如圖所示，質(zhì)量為
的物體2放在正沿平直軌道向右行駛的車廂底板上，并用豎直細(xì)繩通過光滑定滑輪連接質(zhì)量為
的物體，與物體l相連接的繩與豎直方向成
角，則下面說法正確的是
A．車廂的加速度為
B．繩對物體1的拉力為
C．底板對物體2的支持力為
D．物體2所受底板的摩擦力為
8．物體A、B、C均靜止在同一水平面上，它們的質(zhì)量分別為mA、mB、mc，得到三個物體的加速度a與其所受拉力F的關(guān)系如圖所示，圖中A、B兩直線平行，則下列由圖線判斷所得的關(guān)系式正確的是
A．µＡ＝µＢ＝µＣ
B．mA<mB<mc
Ｃ．mA>mB>mC
D．µA<µB＝µC
9．如圖所示，一根輕彈簧的一端系在O點，可自由伸長到B處．今用一小物體m壓住彈簧，且將彈簧壓縮到A處，然后釋放，則小物體能運動到C處靜止．物體與水平地面間的動摩擦因數(shù)恒定，則下列說法正確的是
A．物體從A到B的速度越來越大，從B到C的速度越來越小
B．物體從A到B的速度越來越小，從B到C加速度不變
C．物體從A到B先加速后減速，從B到C一直做減速運動
D．物體在B點受合力一定為零
10．力單獨作用在物體上時產(chǎn)生的加速度為
,力單獨作用在物體上時產(chǎn)生的加速度為
.那么力和同時作用在物體上時產(chǎn)生的加速度
的范圍是
A． 0≤a≤6m／s2
B． 4m／s2≤a≤5m／s2
C． 4m／s2≤a≤6m／s2
D． 0≤a≤4m／s2
11．如圖所示, 將完全相同的兩小球
、
用細(xì)繩懸于以
的速度向右勻速運動的小車頂部，兩球分別與小車的前、后壁接觸，由于某種原因，小車在
的時間內(nèi)停止，此時懸線的拉力之比
為（
）
A．1：1 B．1：2 C．1：3 D．1：4
12．如圖所示，在光滑的水平面上，質(zhì)量分別為m1和m2的木塊A和B之間用輕彈簧相連，在拉力F作用下，以加速度a做勻加速直線運動．某時刻突然撤去拉力F，此瞬時A和B的加速度分別為a1和a2，則下面結(jié)果正確的是
A．a(chǎn)1＝a2=0
B．a(chǎn)1=a，a2=0
C．a(chǎn)1=
，a2=
D．a(chǎn)1=a，a2=-
13．像打點計時器一樣，光電計時器也是一種研究物體運動情況的常用計時儀器，其結(jié)構(gòu)如圖甲所示，a、b分別是光電門的激光發(fā)射和接收裝置，當(dāng)有物體從a、b間通過時，光電計時器就可以顯示物體的擋光時間。
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(1)B升起過程中，底座對地的壓力有多大？
豎直上拋，在不計空氣阻力的理想狀況下，小球?qū)⑸仙侥骋蛔畲蟾叨取Ｓ捎谟锌諝庾枇�，小球�(qū)嶋H上升的最大高度只有該理想高度的80%.設(shè)空氣阻力大小恒定，求小球落回拋出點時的速度大小
.
的木塊為
的速度水平地滑上原來靜止的平板小車，小車質(zhì)量
，小車足夠長，木塊和小車間的動摩擦因數(shù)
，取
。
①
②
。
，
，
，
，
，
，
。
(舍去)。
得 :
．
。
,
,
,
,
,
;（2）
; （3）
.
，
，
，
，
，
，
。學(xué)卷.files/image002.gif)
鄭州四中2008-2009學(xué)年上期高二年級期中考試
14.在等邊三角形的三個頂點a、b、c處，各有一條長直導(dǎo)線垂直穿過紙面，導(dǎo)線中通有大小相等的恒定電流，方向如圖。過c點的導(dǎo)線所受安培力的方向
15.一個T型電路如圖所示，電路中的電
, 
.另有一測試電源，電動勢 為100V，內(nèi)阻忽略不計。則
B. 當(dāng)ab端短路時，cd之間的等效電阻是40
16.如圖所示，同一平面內(nèi)的三條平行導(dǎo)線串有兩個最阻R和r，導(dǎo)體棒PQ與三條導(dǎo)線接觸良好；勻強磁場的方向垂直紙面向里。導(dǎo)體棒的電阻可忽略。當(dāng)導(dǎo)體棒向左滑動時，下列說法正確的是
A.
t′＝t1 ,d=S
B. t′=
D. t′=
18.一滑塊在水平地面上沿直線滑行，t=0時其速度為
則以下關(guān)系正確的是
B. 
C. 
D. 
【解析】本題考查v-t圖像、功的概念。力F做功等于每段恒力F與該段滑塊運動的位移（v-t圖像中圖像與坐標(biāo)軸圍成的面積），第1秒內(nèi)，位移為一個小三角形面積S，第2秒內(nèi)，位移也為一個小三角形面積S，第3秒內(nèi)，位移為兩個小三角形面積2S，故W1=1×S，W2=1×S，W3=2×S，W1＜W2＜W3 。
逆時針勻速轉(zhuǎn)動。若以線圈平面與磁場夾角
時（如圖b）為計時起點，并規(guī)定當(dāng)電流自a流向b時電流方向為正。則下列四幅圖中正確的是
A.若小車向左運動，N可能為零
21.如圖所示，C為中間插有電介質(zhì)的電容器，a和b為其兩極板；a板接地；P和Q為兩豎直放置的平行金屬板，在兩板間用絕緣線懸掛一帶電小球；P板與b板用導(dǎo)線相連，Q板接地。開始時懸線靜止在豎直方向，在b板帶電后，懸線偏轉(zhuǎn)了角度a。在以下方法中，能使懸線的偏角a變大的是
＝
（用被測物理量的字母表示，重力加速度為g）.與真實值相比，測量的動摩擦因數(shù)
（填“偏大”或“偏小”
）。寫出支持你的看法的一個論據(jù)：
③
④
⑤
⑥
⑦
24.(17分)
，A點與原點O的距離為d。接著，質(zhì)點進入磁場，并垂直于OC飛離磁場。不計重力影響。若OC與x軸的夾角為
（2）sin3φcosφ
②
③
⑦
⑨
從動輪做逆時針轉(zhuǎn)動
n 
n
(2)（10分）一足夠長的斜面，最高點為O點，有一長為l=
(Ⅰ)當(dāng)木條A端剛剛離開斜面時，受力情況如圖a所示。設(shè)斜面傾角為，根據(jù)力矩平衡條件，若滿足條件
①
②
③
④
＞
⑤
＞
塞上方液體逐漸流出。在此過程中，大氣壓強與外界的溫度保持不變。關(guān)于這一過程，下列說法正確的是
。（填入選項前的字母，有填錯的不得分）
(2)（9分）一定質(zhì)量的理想氣體被活塞封閉在可導(dǎo)熱的氣缸內(nèi)，活塞相對于底部的高度為h，可沿氣缸無摩擦地滑動。取一小盒沙子緩慢地倒在活塞的上表面上。沙子倒完時，活塞下降了h/4。再取相同質(zhì)量的一小盒沙子緩慢地倒在活塞的上表面上。外界天氣的壓強和溫度始終保持不變，求此次沙子倒完時活塞距氣缸底部的高度。
①
②
′
③
④
(2)（9分）一半徑為R的1/4球體放置在水平面上，球體由折射率為
的透明材料制成。現(xiàn)有一束位于過球心O的豎直平面內(nèi)的光線，平行于桌面射到球體表面上，折射入球體后再從豎直表面射出，如圖所示。已知入射光線與桌面的距離為
。求出射角。
（2）60°
①
②
③
⑤
Pu經(jīng)過
次衰變和
次衰變，最后變成鉛的同位素
。（填入鉛的三種同位素
Pb、
Pb、
Pb中的一種）
(2)（9分）某同學(xué)利用如圖所示的裝置驗證動量守恒定律。圖中兩擺擺長相同，懸掛于同一高度，A、B兩擺球均很小，質(zhì)量之比為1∶2。當(dāng)兩擺均處于自由靜止?fàn)顟B(tài)時，其側(cè)面剛好接觸。向右上方拉動B球使其擺線伸直并與豎直方向成45°角，然后將其由靜止釋放。結(jié)果觀察到兩擺球粘在一起擺動，且最大擺角成30°。若本實驗允許的最大誤差為±4％，此實驗是否成功地驗證了動量守恒定律？
、
，擺長為l，B球的初始高度為h1，碰撞前B球的速度為vB.在不考慮擺線質(zhì)量的情況下，根據(jù)題意及機械能守恒定律得
①
②
④
⑤
⑥
⑦
≤4%
⑧