13. A new technique_________, the yields as a whole increased by 20 percent.

A.working out

B.having worked out

C.having been worked out

D.to have been worked out

10. Switzerland refused to_________ the two world wars.

A.take part                                    B.take sides in

C.join                                        D.attend

. — I sent him the dictionary by mail this morning .

—You ____ that; he''s coming tomorrow afternoon .

A . needn''t have done   B . didn''t have to    C . needn''t do   D . mustn''t do

8. Mr Black is the professor_________I have the greatest respect.

A.to whom                                   B.for whom

C.whom                                     D.who?

10. She stepped into the bedroom quietly  _____she might wake up her roommates.

A. for fear that        B. so long as

C. on condition that    D. in order that

19. Mr Smith,       of the      speech, started to read a novel.

A. tired; boring     B. tiring; bored

C. tired; bored      D. tiring; boring

Each of the students in our class　______ great interest in English and we each_____　　　a copy of A New English-Chinese Dictionary.

A. shows； have  B. show； has  C. are； has  D. is； have

If you ______  the medicine, you____  better now.

A．took, would feel              B．had taken, felt

C．had taken, would feel             D．took, would have felt

It was ______ the old worker came that we______ the experiment.

A．until；didn’t begin      B．not until; began   C．until; began      D．not until; didn’t begin

Zhuhou, _______ on the Xiang River, is an important city, second only to Changsha.

A. located            B. locating             C. being located   D. to be located