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1．在用插針法測(cè)定玻璃磚的折射率的實(shí)驗(yàn)中，甲、乙、丙三位同學(xué)在紙上畫出的界面aa′、bb′與玻璃磚位置的關(guān)系分別如圖實(shí)－10－8①、②和③所示，其中甲、丙兩同學(xué)用的是矩形玻璃磚，乙同學(xué)用的是梯形玻璃磚．他們的其他操作均正確，且均以aa′、bb′為界面畫光路圖．

(1)甲同學(xué)測(cè)得的折射率與真實(shí)值相比________(填“偏大”“偏小”或“不變”)．

(2)乙同學(xué)測(cè)得的折射率與真實(shí)值相比________(填“偏大”“偏小”或“不變”)．

(3)丙同學(xué)測(cè)得的折射率與真實(shí)值相比________．

解析：用圖①測(cè)定折射率時(shí)，玻璃中折射光線偏折大了，所以折射角增大，折射率減小；用圖②測(cè)折射率時(shí)，只要操作正確，與玻璃磚形狀無關(guān)；用圖③測(cè)折射率時(shí)，無法確定折射光線偏折的大小，所以測(cè)得的折射率可大、可小、可不變．

答案：(1)偏小　(2)不變　(3)可能偏大、可能偏小、可能不變

根據(jù)以下提示寫一篇短文，詞數(shù) 60 左右。

劉明是個(gè)中學(xué)生，每天大約六點(diǎn)半離家去上學(xué)，學(xué)校離他家約三公里。他通常走路去，這要花半小時(shí)；下雨天就乘公共汽車，這只花十分鐘，但他更喜歡走路上學(xué)。

52. How far____ your friend ___(live) from school?　 It’s about ten (minute) ride.

51. Lu Hai　 ____ (have) breakfast at 6:30 o very morning.

50. The early bus___ (take) her to school at 7:30.

49. There are____ (hundred) of students in that school.

48. It usually takes ____ (I) two hours ____ (finish) my work every day.

Once there 28__ an old man in a town. He always 29 _a lot of things. so his wife always had to say to him “Don’t forget this.”

One day he went on a long way 30 _. Before he left home, his wife said, “Now you have all these things. You need them 31__ your way. Take 32__ of your things on the way.” He went to the station. He bought a ticket and got on the train 33 it.

About an hour 34__ , the conductor began to 35__ the tickets. He came to the old man and said. “Will you please 36 _me your ticket?” The old roan looked for his ticket in all his pockets 37__he couldn’t find it. He was very 38 __. “I can’t find my ticket. I really bought a ticket before I got on the train,” said the old man.

“I think you are right. I believe you bought a ticket. All right you don’ t have to buy 39__ ticket .” said the conductor kindly. But the old man 40looked worried and said sadly. “You don’t know 41 I’m worried. If I don’t find my ticket, I can’t remember my station 42 　I am going.

28. 　A. had 　B. were 　C. lived 　D. stood

29. 　A. forget 　B. forgets 　C. forgot 　D. forgotten

30. A. alone　 　B. lonely 　C. himself　 　D. along

31. A. in 　　B. on　 　C. at 　D. to

32. A. out 　B. care 　C. much 　D. careful

33. A. and 　B. with 　C. for 　D. without

34. A. later 　B. late　 　C. latest　 D. after

35. A. watch 　B. see　 　C. look　 　D. read

36. A. show 　B. shows 　C. to give 　D. give

37. A. so　 　B. and 　C. but 　D. or

38. A. glad 　B. worried 　C. tired 　D. careful

39. A. another　 B. other 　C. the 　D. the other

40. A. still 　B. even 　C. just 　D. ever

41. A. what 　B. why 　C. that 　D. if

42. A. where 　B. how 　C. whether　 　D. when

A: Hello, Dave! Glad to see you here. What are you going to do 18　 the coming vacation?

B: I have no idea. 19__ about you?

A: I’m going to Kunming 20__ my parents?

B: Great. Kunming is a good place to have 21__ I think you’re going to have a wonderful 22_

A: I think so. Why 23__ you go with me?

B: Sorry. I can’t. But 24 __I’m going to my hometown.

A: Is your hometown far 25__here?

B: Not very far. I can 26__ the bus there.

A: When are you 27__for your hometown?

B: The day after tomorrow.