18. _________, the compass was first in China.

A. It is known to all　　 　　　　　　　　　 B. It is known that

C. We all know　　　 　　　　　　　　　　　 D. As is known to all

17. At the school gate stands a blackboard, ______ reads “Welcome back”.

A. which　 　　　　　 B. that　 　　　　　　 C. on which　　 　　　 D. where

16. The children climbed the hill, ______ they picnicked.

A. on its top　 　　　　　　　　　　　　　　　　 B. on the top of it

C. on whose top　 　　　　　　　　　　　　　 D. on the top of that　

15. Gone are the days ______ Shanghai was a paradise for imperialist adventures.

A. that　　 　　　　　 B. which 　　　　　　 C. when　 　　　　　　　 D. during

14. Last summer we visited the West Lake ______ Hangzhou is famous in the world.

A. in which 　　　　　 B. for that 　　　　　 C. in that 　　　　　　　　 D. for which

13. This is the most important chapter ______ we should pay attention.

A. to whom 　　　　 B. in which　 　　　 C. at which 　　　　　　 D. to which

12. China has hundreds of islands, ________ the largest is Taiwan.

A. in which 　　　　　 B. at which　 　　　 C. of which　 　　　　　 D. which

11. The radio I bought yesterday is quite different from _____ you bought last month.

A. that　 　　　　　　 B. which　 　　　　 C. the one　 　　　　　 D. the one what

10. I, ______ your good friend, will try my best to help you out.

A. who is　 　　　　　 B. who am 　　　　　 C. that is 　　　　　　　　 D. what is

9. He has two sons, _______ work as chemists.

A. two of whom　　　 　　　　　　　　　　 B. both of whom　

C. both of which　　　 　　　　　　　　　　 D. all of whom