6.　　　 溯源；追溯到…　　　　　 trace back (to)

5.　　　 进城　　　　　　　　　　 go to town

4.　　　 周游世界　　　　　　　　 make a tour of the world

3.　　　 漫游，巡回，周游　　　　 go on a tour

2.　　　 与…取得联系　　　　　　 get in touch with

1.　　　 总计　　　　　　　　　　 in total

50.　 ______book of this writer is East and West.

A. Known to be the best　 　　　　　 B. It was the best known

C. Known as the best　　 　　　　　 D. The best known

49.　 Their cheerful voices showed that they were having a ______ discussion.

A. noisy　　 　 B. serious　 　　　　 C. complete　 　　　 D. friendly

48.　 Last night I had a terrible cold and ached all _____.

A. the way　 B. over　 　　　　　　 C. at once　 　　　　 D. the worst

47.　 -Are you satisfied with her answer?

-Not at all. It couldn’t have been _____.

A. worse　 　　　 B. so bad　　 　　　　 C. better　 　　　　　 D. the worst