20. The tallest building _____ I like most is the one_____windows face the lake.

A. /; which B. /; that　　 C. that; whose　　 　 D. which; whose

19.The roof fell _____ he had time to rush out.

A．until　 　　　　 B．before　　　 　　 C．when　　　　 D．since

18. Once _____ what to do, these computers will show great power in carrying it out.

A．to teach　　　　　 B．teaches　　　　 C．teaching　　　 D．taught

17. -Who knows where Terry is?

-The reason _____Terry is absent is _____his father had an accident.

A. why, because　 B. why, that　 C. that, because　　 D. that , /

16. Do you know the difficulty he had ____ the work?

A. on finishing　　　　　 　B. with finishing 　　

C. finishing　 　　　　　　D. having finished

15．He is clever, but ____, he makes many mistakes.

A．on the contrary 　　　　　　　　　　 B．on the other side　

C．on the other hand　 　　　　　　　　 D．on one hand

14. The secretary worked late into the night,_____ a long speech for the president.

A. to prepare　 B. preparing　 C. prepared　　 D. was preparing

13.John was caught ____ the earthquake ____ caused a lot of damage.

A．by; which　 　　　　 B．in; which　 　 C．by; in which　　 　　 D．in; in which

12. The teacher said _____.

A.the earth moves around the sun.　　 B.Susan will fail in the exam.

C.you are right.　　　　　　　　　　 　　　 D. he will go with us.

11. In order to _____ money to _____ his family, he left the village and found a job in a faraway city.

A. get, raise　　 B. look for, keep　 C. earn, grow　 D. make , keep