1．在用插针法测定玻璃砖的折射率的实验中，甲、乙、丙三位同学在纸上画出的界面aa′、bb′与玻璃砖位置的关系分别如图实－10－8①、②和③所示，其中甲、丙两同学用的是矩形玻璃砖，乙同学用的是梯形玻璃砖．他们的其他操作均正确，且均以aa′、bb′为界面画光路图．

(1)甲同学测得的折射率与真实值相比________(填“偏大”“偏小”或“不变”)．

(2)乙同学测得的折射率与真实值相比________(填“偏大”“偏小”或“不变”)．

(3)丙同学测得的折射率与真实值相比________．

解析：用图①测定折射率时，玻璃中折射光线偏折大了，所以折射角增大，折射率减小；用图②测折射率时，只要操作正确，与玻璃砖形状无关；用图③测折射率时，无法确定折射光线偏折的大小，所以测得的折射率可大、可小、可不变．

答案：(1)偏小　(2)不变　(3)可能偏大、可能偏小、可能不变

根据以下提示写一篇短文，词数 60 左右。

刘明是个中学生，每天大约六点半离家去上学，学校离他家约三公里。他通常走路去，这要花半小时；下雨天就乘公共汽车，这只花十分钟，但他更喜欢走路上学。

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.