22. There is no light in the dormitory. They must have gone to the lecture, ________?

A. didn't they　 　B. don't they　 　C. mustn't they　　 D. haven't they

21. It is almost five years　 　　　　　we saw each other last time.

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

20. _________ I explained on the phone, your request will be considered at the next meeting.

　　　 A．When　　　　　　　　 B．After 　　　　　　　　 C．As　　　　　　　　 D．Since

19.　 The president spoke at the business meeting for nearly an hour without _________ his notes.

　　　 A．bringing up　　　　 B．referring to 　　　　 C．looking for　　　 　D．trying on

18.　 The country life he was used to ______ greatly since 1992.

　　　 A. change　　　　　　　 B. has changed　　　　　　　 C. changing　　　　　 D. have changed

17.　 With more forests being destroyed, huge quantities of good earth ______ each year.

　　　 A. is washing away　　　　　　　　　　　　　　　　　　　　　 B. is being washed away

　　　 C. are washing away　　　　　　　　　　　　　　　　　　　　　　　　 D. are being washed away

16．In the dark forests ________, some large enough to hold several English towns.

　　　 A．stand many lakes　　　　　　　　　　　　　　　　 B．lie many lakes

　　　 C．many lakes lie　　　　　　　　　　　　　　　　　　 D．many lakes stand

15．Nowadays, a large number of women, especially those from the countryside, _________ in the clothing industry.

　　　 A．is working 　　　　 B．works　　　　　　　　 C．work　　　　　　　　　 D．worked

14．-Must I turn off the gas after cooking ?

　　 -Of course . You can never be　 　　　　　careful with that .

　　　 A．enough 　 B．too 　 C．so 　　 D．very

13．The manager, _______ it clear to us that he didn’t agree with us, left the meeting room.

　　　 　A．who has made　　　 B．having made　　　　 C．made　　　　　　　 D．making