47. What is the main topic of the talk?
48. According to the professor, what was the major change in the agriculture during the 19th century?
49. According to the professor, what was one result of the increased use of machinery on farms of the United States?
50. According to the professor, why was world market important for the United States agriculture?
答案：ADBCA BCADC ACCBD ACDDB DDCBA ADDDA BDCCB CDACD BBCDB CDABC


Part2听力原文

22. (woman) I'm looking for a lightweight jacket…navy blue…medium…
(man) Let's see. Have you checked the sales rack in the back? There were still a few there yesterday.
(narrator) What does the man mean?


27. (woman) When's a good time to get together to discuss our history project?
(man) Other than this Wednesday, one day's as good as the next.
(narrator) What does the man mean?

28. (man) Congratulations! I heard your field hockey team is going to the mid-Atlantic championships!
(woman) Yeah! Now were all working hard to get ready for our game tomorrow.
(narrator) What will the woman probably do this afternoon?

29. (man) Can you come over for dinner tonight?
(woman) I'm up to my ears in work, so I'll have to take a rain check.
(narrator) What does the woman mean?

30. (woman) If you rub some soap on that drawer, it might stop sticking.
(man) Well, maybe, but if I took out the paper that has fallen down in back, that would help, for sure.
(narrator) What is the problem?


答案：DDDDA