湖北省省實驗中學2009屆高三年級理科綜合能力測試（十）        命題人：黃瓊 高曉軍 龍信和        時間：150分鐘  總分300分

第I卷（共126分）

以下數(shù)據(jù)可供解題時參考：相對原子質量（原子量）： Mg   24； Al  27

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本資料來源于《七彩教育網(wǎng)》http://www.7caiedu.cn

《解三角形》

試題詳情

海南省國興中學 海師附中 嘉積中學 三亞一中2009年高三聯(lián)考物理科試卷

注意事項：

1．本試卷分第I卷（選擇題）和第II卷（非選擇題）兩部分。答卷前，請考生務必將自己的姓名、準考證號填寫在答題卡上。

2．回答第I卷時，選出小題答案后，用鉛筆把答題卡上對應題目的答案標號涂黑。如需改動，用橡皮擦干凈后，用再選涂其它答案標號。寫在本試卷上無效。

3．回答第II卷時，將答案寫在答題卡上。寫在本試卷上無效。

4．考試結束后，將本試卷和答題卡一并交回。

第Ⅰ卷（選擇題，共34分）

試題詳情

揭陽華僑中學高三物理練習題 2009-05-07

1.下面列舉的事例中正確的是(     ).

A．居里夫婦用α粒子轟擊鋁箔時發(fā)現(xiàn)了正電子

B．盧瑟福的原子結構學說成功地解釋了氫原子的發(fā)光現(xiàn)象

C．麥克斯韋從理論上預言了電磁波的存在,赫茲用實驗方法給予證實

D．玻爾建立了量子理論,解釋了各種原子發(fā)光現(xiàn)象

2.氫原子的核外電子從一個軌道躍遷到另一軌道時,可能發(fā)生的情況有

A．放出光子,電子動能減少,原子勢能增加

B．放出光子,電子動能增加,原子勢能減少

C．吸收光子,電子動能減少,原子勢能增加

D．吸收光子,電子動能增加,原子勢能減少

3.如圖所示,一驗電器與鋅板相連,現(xiàn)用一弧光燈照射鋅板,關燈后,指針保持一定偏角,下列判斷中正確的是

A．用一帶負電(帶電量較少)的金屬小球與鋅板接觸,則驗電器指針偏角將增大

B．用一帶負電(帶電量較少)的金屬小球與鋅板接觸,則驗電器指針偏角將減小

C．使驗電器指針回到零后,改用強度更大的弧光燈照射鋅板,驗電器指針偏角將比原來大

D．使驗電器指針回到零后,改用強度更大的紅外線燈照射鋅板,驗電器指針一定偏轉

4．放在光滑水平面上的物塊1、2用輕質彈簧秤相連，如圖所示．今對物塊1、2分別施以相反的水平力F₁ 、F₂．且F₁大于F₂，則彈簧秤的示數(shù)

A．一定等于F₁＋F₂

B．一定等于F₁－F₂               

C．一定大于F₂小于F₁

D．條件不足，無法確定

5．如圖所示，斜面體P放在水平面上，物體Q放在斜面上．Q受一水平作用力F，Q和P都靜止．這時P對Q的靜摩擦力和水平面對P的靜摩擦力分別為f₁、f₂．現(xiàn)使力F變大，系統(tǒng)仍靜止，則

A． f₁、f₂都變大           B．f₁、f₂都不一定變大

C． f₁變大，f₂不一定變大   D． f₂變大，f₁不一定變大 

6．如圖所示，質量為m的木塊在質量為M的長木板上向右滑行，木塊同時受到向右的拉力F的作用，長木板處于靜止狀態(tài)；已知木塊與木板間的動摩擦因數(shù)為μ₁，木板與地面間的動摩擦因數(shù)為μ₂，則

A．木板受到地面的摩擦力的大小一定是μ₁mg

B．木板受到地面的摩擦力的大小一定是μ₂（m十M）g

C．當F＞μ₂（m＋M）g時，木板便會開始運動

D．無論怎樣改變F的大小，木板都不可能運動

7．如圖所示，在臺秤的托盤上放著一個支架，支架上掛著一個電磁鐵A，電磁鐵的正下方有一鐵塊B，電磁鐵不通電時，臺秤示數(shù)為G，當接通電路，在鐵塊被吸起上升的過程中，臺秤的示數(shù)將                                           

A．不變                                       B．變大

C．變小                                           D．忽大忽小

8．如圖所示，甲、乙兩電路中電源完全相同，電阻R₁>R₂，在兩電路中分別通過相同的電量Q的過程中，下列關于兩電路的比較，正確的是

  A．電源內部產(chǎn)生電熱較多的是甲電路中的電源

  B．R₁上產(chǎn)生的電熱比R₂上產(chǎn)生的電熱多

  C．電源做功較多的是乙電路中的電源

  D．電源輸出功率較大的是乙電路中的電源

9.如圖所示，一個帶負電的油滴以初速v₀從P點傾斜向上進入水平方向的勻強電場中，若油滴到達最高點時速度大小仍為v₀，則油滴最高點的位置在

A．P點的左上方     B．P點的右上方

C．P點的正上方     D．上述情況都可能

10．如圖所示，在圓形區(qū)域內存在一垂直于紙面向里的勻強磁場，一束速率各不相同的質子從A點沿磁場圓形邊界的半徑方向射入磁場。關于質子在該磁場內運動過程的說法正確的是

A．運動時間越長的，其軌跡越長

B．運動時間越長的，其射出磁場時的速率越大

C．運動時間越長的，其軌跡對應的圓心角越大

D．運動時間越長的，其速度方向的偏轉角越大

11．如圖所示，寬h=2cm的有界勻強磁場，縱向范圍足夠大，磁感應強度的方向垂直紙面向內，現(xiàn)有一群正粒子從O點以相同的速率沿紙面不同方向進入磁場，若粒子在磁場中做勻速圓周運動的軌道半徑均為r=5cm，則

A．右邊界:-4cm<y<4cm有粒子射出

B．右邊界:y>4cm和y<-4cm有粒子射出

C．左邊界:y>8cm有粒子射出

D．左邊界:0<y<8cm有粒子射出

12．如圖所示，平行于紙面水平向右的勻強磁場，磁感應強度B₁＝1T。位于紙面內的細直導線，長L＝1m，通有I＝1A的恒定電流。當導線與B₁成60⁰夾角時，發(fā)現(xiàn)其受到的安培力為零。則該區(qū)域同時存在的另一勻強磁場的磁感應強度B₂大小可能值

A．T      B．T   

C．1 T       D．T

13．(Ⅰ) (10分)某同學設計了一個探究加速度與物體所受合力F及質量m間關系的實驗．圖（a）為實驗裝置簡圖，A為小車，B為打點計時器，C為裝有砂的砂桶，D為一端帶有定滑輪的長方形木板，實驗中認為細繩對小車拉力F等于砂和砂桶總重力，小車運動加速度a可由紙帶上點求得．

次   數(shù)

1

2

3

4

5

6

7

8

小車加速度a/ms^－2

1.90

1.72

1.49

1.25

1.00

0.75

0.50

0.30

小車質量m/kg

0.25

0.29

0.33

0.40

0.50

0.71

1.00

1.67

4.00

3.50

3.00

2.5

2.00

1.40

1.00

0.60

（1）圖(b)為某次實驗得到的紙帶（交流電的頻率為50Hz），由圖中數(shù)據(jù)求出小車加速度值為          _________m/s²；

（2）保持砂和砂桶質量不變，改變小車質量m，分別得到小車加速度a與質量m及對應的數(shù)據(jù)如表中所示，根據(jù)表中數(shù)據(jù)，為直觀反映F不變時a與m的關系，請在方格坐標紙中選擇恰當物理量建立坐標系，并作出圖線；

從圖線中得到F不變時小車加速度a與 質量m間定量關系是_____________；

（3）保持小車質量不變，改變砂和砂桶質量，該同學根據(jù)實驗數(shù)據(jù)作出了加速度a與合力F圖線如圖（C），該圖線不通過原點，明顯超出偶然誤差范圍，其主要原因是：

                                                                        .

 (Ⅱ)某同學用如圖所示的實驗裝置探究小車動能變化與合外力對它所做功的關系。圖中A為小車，連接在小車后面的紙帶穿過打點計時器B的限位孔，它們均置于水平放置的一端帶有定滑輪的足夠長的木板上，C為彈簧測力計，不計繩與滑輪的摩擦。實驗時，先接通電源再松開小車，打點計時器在紙帶上打下一系列點。

（1）該同學在一條比較理想的紙帶上，從點跡清楚的某點開始記為O點，順次選取5個點，分別測量這5個點到O之間的距離，并計算出它們與O點之間的速度平方差：

 ，填入下表：

以為縱坐標，以s為橫坐標在方格紙中作 

出圖象.若測出小車質量為0.2kg，結合圖 

象可求得小車所受合外力的大小為      N

（2）若該同學通過計算發(fā)現(xiàn)小車所受合外力小于測

力計讀數(shù)，明顯超出實驗誤差的正常范圍．你認

為主要原因是                            ，

實驗操作中改進的措施是                 

                                            。

14．在實驗室中測量電源的電動勢和內電阻，可以提供的器材有：

a）待測電池：電動勢E（約3V）、內電阻r（約1Ω）

b）電壓表V：量程15V，內電阻

c）電流表A₁：量程0.6A，內阻

d）電流表A₂：量程1mA，內阻r₂=200Ω

e）滑動變阻器R₁：阻值0―200Ω，額定電流1.5A

f）滑動變阻器R₂：阻值0―20Ω，額定電流1.5A

g）電阻箱R₃：9999Ω

以及開關，導線，坐標紙等。

為了盡可能準確地測量待測電池的電動勢和內電阻：

①實驗所用器材除了待測電池和導線、開關、坐標紙等，還需選擇必要的器材有（填器材前的序號）               。

②畫出測量電池電動勢和內電阻的電路圖。

③說明測量的主要實驗步驟。（要求用圖象法處理實驗數(shù)據(jù)。）

15．如圖，圓環(huán)質量為M，經(jīng)過環(huán)心的豎直鋼絲AB上套一質量為m的小球，今將小球沿鋼絲AB以初速度v₀從A點豎直向上拋出，致使環(huán)對地面剛好無壓力，求：

⑴ 小球上升的加速度。

⑵ 小球能達到的最大高度。（球不會碰到B點）

16．(16分)如圖所示，MN為紙面內一豎直分界線，P、D是紙面內水平方向上的兩點。兩點之間的距離為L，D點距分界線的距離為，一質量為m、電量為q的帶正電粒子在紙面內從P點開始以v₀的水平初速度向右運動，經(jīng)過一段時間后在MN左側空間加上垂直紙面向里的磁感應強度為B的勻強磁場，磁場維持t₀時間后撤除，隨后粒子再次通過D點且速度方向豎直向下。粒子的重力不計，求：

  (1) 粒子在加上磁場前運動的時間t．    、

  (2) 滿足題設條件的磁感應強度B的最小值及B最小時t₀的值．

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本資料來源于《七彩教育網(wǎng)》http://www.7caiedu.cn

  《算法初步》

試題詳情

試題詳情

2009屆巢湖市第六中學高三

第六次月考

第一部分  聽力（共兩節(jié)，滿分30分）

第一節(jié)（共5小題；每小題1.5分，滿分7.5分）

       聽下面5段對話。每段對話后有一個小題，從題中所給的A、B、C三個選項中選出最佳選項，并標在試卷的相應位置。聽完每段對話后，你都有10秒鐘的時間來回答有關小題和閱讀下一小題。每段對話僅讀一遍。

1. Which is the first program the woman is planning to watch?

A. A movie.        B. A cartoon.     C. A football game.

2. What can we learn from this conversation?

A. The wind has stopped but it's still raining.    B. The rain stopped.

C. It's still raining and the wind is blowing.

3. What country does Suzanne presently call her home?

A. America.        B. England.       C. Spain.

4. Where does the conversation take place?

A. In the man's house.    B. In a dinning-room.    C. In a restaurant.

5. What job is the man poking for?

A. He wants to be with the computer center.

B. He wants to work at a computer servicing company.

C. He wants to work in the computer market department.

第二節(jié) （共15小題；每題1.5分，滿分22.5分）

聽下面5段對話或獨白。每段對話或獨白后有幾個小題，從題中所給的A，B，C三個選項中選出最佳選項，并標在試卷的相應位置。聽每段對話或獨白前，你將有時間閱讀各個小題，每小題5秒鐘；聽完后，每小題將給出5秒鐘的作答時間。每段對話或獨白讀兩遍。

聽第6段材料，回答第6―7題。

6. What kind of car does the woman want?

A. A new car.      B. A second-hand car.     C. A cheap car.

7. What happened to the woman's car?

A. It broke down.   B. It was stolen.     C. It was given to her son.

聽第7段材料，回答第8―9題。

8. What does David want Julie to do?

A. To tell him her telephone number.   B. To go out with him.   C. To visit him.

9. When will they meet?

A. On Sunday.     B. On Saturday.           C. On Thursday.

聽第8段材料，回答第10―12題。

10. Which statement is right?

A. The exam yesterday was harder than the last one.

B. The exam yesterday was shorter than the last one.

C. The exam yesterday was as easy as the last one.

11. Why did Mary make some stupid mistakes?

A. Because he didn’t work hard.    B. Because she didn’t take many courses.

C. Because she was too careless.

12. Who is a better student?

A. Mary.      B. Jimmy.  C. The man.

聽第9段材料，回答第13―16題。

13. Who is answering the call?

A. Mary.      B. Jean.     C. Anna

14. Why is Pat making the telephone call?

A. To tell his friend to attend a meeting.

B. To tell his friend to hand in the experiment report.

C. To tell his friend to come to work for the Chemistry Department.

15. Who is Jean?

A. Annals sister-in-law.   B. Mary's sister-in-law.   C. Pat's friend.

16. Which of the following do you think is true?

A. Pat knows Mary.    B. Jean knows Pat.    C. Anna doesn't know Pat.

聽第10段材料，回答第17―20題。

17. What is the purpose of the talk?

A. To describe a college training course.   B. To employ people for a job.

C. To talk about problems the airline company faces.

18. According to the speaker, how many people are accepted for the training program every year?     A. About one thousand.   

B. Several thousand.   C. Fewer than one thousand.

19. What subject matter does the speaker mention is included in the training?

A. Psychology.         B. Physical language.  C. Geography.

20. Why does the speaker mention headwaiters?

A. To explain her previous job.

B. To describe the background needed by people asking for the job.

C. To describe some of the skills people working in the plane need.

­

第二部分：知識運用（共兩節(jié)，滿分45分）

第一節(jié)：單項填空（每小題1分，滿分15分）

從A、B、C、D四個選項中，選出可以填入空白處的最佳選項。

21. ―_______ noise outside!   

―_______. I’ll close the doors and the windows. Now let’s go on.

A. What a; Not at all        B. How; That’s right

C. How; All right           D. What; Never mind

22. The hard-working farmers and their happy life we saw in the countryside________ us very much.

A. frightened          B. impressed            C. disappointed          D. expressed

23. Was it 8 o’clock _______ you heard someone _______ at the door?

A. when; knocking        B. when; knock             C. that; knocking           D. that; knock

24. No computer so far _______ can have the same ability as human brains.

A. be built                    B. having built                     C. being built                D. built

25. _______ Beijing you see today is quite _______ different city from what it used to be.

A. The; 不填               B. The; a                      C. 不填; the                 D. A; a

26. ― It was careless of you _______ your clothes outside all night. 

― My God! ______.

A. to leave; So did I     B. leaving; So do I

C. to have left; So I did D. having left; So do I

27. ― What do you think of the speech?    

― The speaker said _______ nothing worth _______.

A. nearly; listening to   B. hardly; listening

C. scarcely; listening to  D. almost; listening to

28. --I tried to get a hold of Ben last night, but it was so difficult to get through.

--_______. Maybe he was on the Net.

A. That’s probably it    B. That’s strange   C. That’s true D. I know why

29. ― When did he start?     ― He started _______ he got her letter.

A. the moment    B. as long as        C. since        D. until

30. No one would have time to read or listen to an account of everything _______ going on in the world.  

A. it is      B. as is      C. that is   D. what is

31. ― Would you mind _______ me the dictionary? 

― Of course not. But it is ______ my reach.

A. passing; out              B. passing; beyond        C. to pass; far away              D. to pass; out of

32. He was _______ today, but was asked to stay _______ week.

A. to have returned; another   B. returning; one more 

C. returned; another          D. to return; other

33. ―_______ helps others will be helped. 

― So I’ll be thankful to and try to help _______ has helped us.

   A. Whoever; whomever     B. Whoever; whoever 

C. Who; whoever              D. Who; whomever

34. ― Your sister nearly _______ all her spare time to her course during the three years.

   ― That’s right, or she_______ the first place in her school in the 2000 College Entrance Examination.   

A. spent; wouldn’t take    B. devoted; wouldn’t have taken

   C. hadn’t devoted; hadn’t taken  D. hadn’t spent; couldn’t take

35. She’s a teacher, _______ is clear from her manner.

A. that    B. what         C. as       D. who

第二節(jié)：完形填空(共20小題；每小題1.5分，滿分30分)

閱讀下面短文，掌握其大意，然后從短文后所給各題的四個選項(A、B、C和D)中，選出可以填入空白處的最佳選項。

There had been a big battle the day before and our army had taken the enemy's defence works. Night fell and we were in a trench (戰(zhàn)壕) ____36____the enemy had dug as the last ____37____of defence. We could ____38____them digging a new trench ____39____in the distance. And by the morning we could see the ____40____of the spades (鏟子) as they____41____the earth out.

   In our trench, some soldiers ____42____time shooting at the enemy spades to see ____43____they could hit any of them. Then one of the enemy soldiers ____44____our game. He would put his spade up suddenly and ____45____it there for a few seconds to see whether ____46____of us could hit it and then pull it down quickly. ____47____time he would do it in quite a ____48____place. A____49____of our soldiers shot at it ____50____it came up, but none of them ____51____to have hit it. Then there came a time when the spade ____52____down for much longer than ____53____. We thought that the soldier was ____54____from playing the game by an officer. But just ____55____we thought that we could not see the spade again, it came up once more with a bandage (繃帶) tied around it.

36. A. where

B. which

C. since

D. when

37. A. result

B. line

C. moment

D. hope

38. A. watch

B. know

C. hear

D. observe

39. A. themselves

B. ever

C. our enemies

D. our game

40. A. tops

B. colors

C. shapes

D. bottoms

41. A. dug

B. carried   

C. threw

D. stole

42. A. spent

B. wasted  

C. grasped

D. enjoyed

43. A. who

B. if

C. how

D. weather

44. A. attends

B. won

C. joined

D. joined in

45. A. keep

B. kept

C. keeping

D. to keep

46. A. all

B. one

C. none

D. each

47. A. Next

B. Other

C. Last

D. Any

48. A. far

B. strange   

C. different

D. various

49. A. sort

B. kind

C. deal

D. number

50. A. suddenly

B. everywhere

C. only

D. whenever

51. A. honored

B. happened

C. expected

D. seemed

52. A. kept

B. remained

C. taken

D. hid

53. A. always

B. usual

C. the rule

D. their expect

54. A. ordered

B. forced

C. prevented

D. left

55. A. then

B. when

C. a minute

D. now

第三部分 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A、B、C、D 四個選項中選出最佳選項。

A

The George Washington School had been standing for more than 100 years. The school building was in good shape, but behind it was an old basketball court. The court’s blacktop had been broken and was overgrown with weeds. The fence around the court was battered, and parts of it lay on the ground. The basketball hoops were bent and rusted.

One cold day in February, Mr. Garson, a biology teacher, was taking a walk during his lunch break. He passed the old basketball court. “What an ugly sight!” he said, groaning. As he stared at the empty court, he had a vision. He stopped and let the vision take shape in his imagination. In his mind, he pictured something quite different from what he actually saw.

Mr. Garson asked the school board for money to turn his vision into a reality. In April he organized a group of community volunteers to tear up the old basketball court and take it away. Then he persuaded a local farmer to bring truckloads of good topsoil free of charge, which several students spread over the field. A group of parents volunteered to build a new fence around the land. Mr. Garson bought some garden tools. He also bought seeds and young plants. In May students planted tomatoes, potatoes, corn, lettuce, onions, and peppers. In one place they planted a dozen kinds of flowers that would bloom through the summer and fall.

Two students checked the garden and watered it every day. On Saturdays throughout the summer, groups of students gathered to weed (除草) the garden and harvest what was ripe. In September students enjoyed eating fresh produce from the George Washington garden for lunch. Most days there were freshly cut flowers on the breakfast tables. In late fall a local farmer plowed under the garden so that it would be ready for planting again in the spring.

 “What a beautiful sight!” Mr. Garson announced a speech at the first school assembly. “It proves that we can change things if we work together toward a common goal.”

56. The best title of this passage is _______.

A. What a basketball court!   B. How hard the work is!

C. We need vegetables!       D. What a sight!

57. In this selection, the word “battered” means_______.

A. damaged   B. repaired   C. locked    D. high

58. What is one theme expressed in this selection?

A. It takes a lot of hard work to get large donations.

B. It is important to eat a lot of fresh fruits and vegetables.

C. You shouldn’t be discouraged if you don’t succeed right away.

D. One person with a vision can make a big difference.

59. How does Mr. Garson get topsoil for the garden?

A. He buys it.       B. The school board supplies it.

C. A local farmer donates it.  D. He finds it under the basketball court.

B

Creativity（創(chuàng)造性）is the key to a brighter future, say education and business experts. Here is how schools and parents can encourage this important skill in children.

    If Dick Drew had listened to his boss in 1925, we might not have a product that we now think or as of great importance: a new type of tape. Drew worked for the Minnesota Mining Company. At work he developed a kind of material strong enough to hold things together. But his boss told him not to think more about the idea. Finally, using his own time, Drew improved the tape, which now is used everywhere by many people. And his former company learned from its mistake. Now it encourages people to spend 15 percent of their work time just thinking about and developing new ideas.

    Creativity is not something one is just born with, nor is it necessarily a character of high intelligence（智力）.The fact that a person is highly intelligent does not mean that he uses it creatively. Creativity is the matter of using the resources one has to produce new ideas that are good for something.

Unfortunately, schools have not tried to encourage creativity. With strong attention to test results and the development of reading, writing and mathematical skills, many educators give up creativity for correct answers. The result is that children can give back information but can't recognize ways to use it in new situations. They may know the rules correctly, but they are unable to use them to work out practical problems.

It is important to give children choices. From the earliest age, children should be allowed to make decisions and understand their results. Even if it's choosing between two food items for lunch, decision-making helps thinking skills. As children grow older, parents should let their children decide how to use their time or spend their money, but not tell them too much if they make the wrong decision. The child may have a hard time, but that is all right. This is because the most important character of creative people is a very strong desire to find a way out of trouble.

60.What did the company where Drew once worked learn from its mistake？

  A. They encouraged people to work a longer time.

B. They discouraged people to think freely.

C. They asked people to spend all their work time developing new ideas.

D. They encouraged people to spend some of their work time considering and improving new ideas.

61. Creativity is something_______.

A. that people are born with       B. that depends on intelligence

C. that is a way of using what one has learned to work out new problems

D. that is not important at all

62.Why don't schools try to encourage creativity？

A. They don't understand the importance of education.

B. They don't want their students to think about anything

  C. They pay too much attention to examination marks, language and mathematical skills.

  D. They think it is very important to remember some information.

63.What should the parents do when their children decide how to spend their money？   A. Try to help them as much as possible

B. Take no notice of whatever they do.

  C. Help them if their decision is wrong, but not too much.

D. Leave them as they are.

C

Geologists have been studying volcanoes for a long time. Though they have learned a great deal, they still have not discovered the causes of volcanic action. They know that the inside of the earth is very hot, but they are not sure exactly what causes the great heat. Some geologists have thought that the heat is caused by the great pressure of the earth's outer layers(層). Or the heat may be left from the time when the earth was formed. During the last sixty years scientists have learned about radium, uranium (鈾), thorium, and other radioactive elements(放射性元素). These give out heat all the time as they change into other elements. Many scientists now believe that much of the heat inside the earth is produced by radioactive elements.

Whatever the cause of the heat may be, we do know that the earth gets hotter the farther down we dig. In deep mines and oil wells the temperature rises about 1ㄈ for each 50 feet. At this rate the temperature 40 miles below the earth's surface would be over 4,000. This is much hotter necessary to melt(融化) rock. However, the pressure of the rock above keeps most materials from melting at their usual melting points. Geologists believe that the rock deep in the earth may be plastic, or puttylike. In other words, the rock yields (屈服) slowly to pressure but is not liquid. But if some change in the earth's crust releases the pressure, the rock melts. Then the hot, liquid rock can move up toward the surface.

 When the melted rock works its way close to the earth's crust, a volcano may be formed. The melted rock often contains steam and other gases under great pressure. If the rock above gives way, the pressure is released.

Then the sudden expansion(膨脹) of the gases causes explosion. These blow the melted rock into pieces of different sizes and shoot them high in the air. Here they cool and harden into volcanic ash. Some of the materials fall around the hole made in the earth's surface. The melted rock may keep on rising and pour out as lava. In this way, volcanic ash and lava build up the mountains that we call volcanoes.

64. The main idea of this passage is the _______.

A. interior (內部) of the earth   B. formation of volcanoes

   C. results of vocalic action      D. work of geologists

65. The cause for the heat in interior of the earth is_______.

A. radioactive elements     B. the great pressure of the earth

C. not determined   D. the heat remaining from the formation of the earth

66. If the temperature at the earth's surface is 20 ㄈ, the temperature in a coal mine 500 feet below the surface would, in degrees, _______.  

A. 30      B. 40        C. l20    D. 500

D

In cars of normal design, the petrol system is made up of three parts: storage tanks, a pump and a carburetor（汽化器）.

       The petrol tank is fitted at the back of the car where it is out of the way, yet easily filled at a gas station. Tanks are in various capacity but they usually hold enough petrol for 250~300 miles running. Because the tank is at the opposite end of the car from the carburetor, which is fitted high up on the engine, a pump is needed to draw the petrol from one to the other, as it is from the carburetor that the petrol in finally fed into the engine. Pumps can be of two kinds: electrically operated or mechanically driven from the engine.

67. Which of the following pictures shows the correct petrol system described in this passage?