Which do you enjoy _____ your weekend, swimming or fishing?

 A. spending  B. being spent  C. spend  D. to spend

—Shall I sit at this end of the boat or the other end?

  —If you keep still, you can sit at      end.

  A. neither   B. each   C. either  D. any

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

— ________ did the professor give you much advice?

— The choice of a career.

A. On what       B. In what         C. What   D. For what

________ a difficult situation, so you should send him a message and give him some advice.

A. As he is in    B. He is in         C. Being in        D. He being in

“May I borrow your paper?” “ ________.”

A. By all means         B. Never mind C. You are welcome          D. Don’t mention it

The man showed us so heavy a stone ________ no man can lift.

A. that      B. as             C. which          D. and

In warm weather fruit and meat ________ long.

A. don’t keep      B. can’t be kept

C. are not kept     D. aren’t keeping

A new technique ____ out, the yields (收成) increased by 20% .

A. having working        B. having been working 

C. has worked            D. had been worked

. New technology ______ to make sure that the cars, taxis, buses and trains we use ______ the air.

A. is used; not to pollute       B. has used; is not polluted

C. is being used; do not pollute     D. has been used; to pollute