Ten percent of the work ______ been finished today.

　 A. had　　　　　 B. has　　　　 C. have　　　　 D. was

The professor can hardly find sufficient grounds ____ his argument in favour of the new theories.

A. on which to base　

B. which to base on　

C. on what to base　　

D. that to base on

—What about the books ?

—Books of this kind 　　　　 well .　　　　　　　　　　　　　　

A．sell 　　　 B．sells 　　　 C．are sold 　 D．is sold

I'll go to the library as soon as I finish what I _____.　　　

A. was doing　　　　 B. am doing　　 C. have done　　　　 D. had been doing

What do you think would happen if there 　　　　　　　　　 no light during the day?

A. were　　　　 B. would be　　　　 　　 C. will be　　 　　D. is

At last the man had no choice but _____ the computers from the office.

　　　 A. admit to have stolen　　 B. admit having stolen

C. to admit to have stolen　 D. to admit having stolen

The reason why I plan to go is _______ if I don’t.
    A. because she will be disappointed 
B. that she will be disappointed
    C. because she will have a disappointment
    D. for she will be disappointed

As we often see, some people work best in tasks alone, ______ others work best in groups.

A. when　　　　 B. since

C. while　　　　 D. because

Nearly every great building in Beijing was built＿ south.

　A.to face B.facing　　C.to have faced D.being facing

Every means _______ tried, but in vain.
    A. have been    B. has been    C. are          D. is