_______ we are doing has never been done before.

    A. That               B. What

    C. Which              D. Whether

The books, ________ the dictionaries, must be put back where they ________.

    A. included； were            B. to include； are

C. including； were           D. including； are 

 They haven’t arrived yet but we _____ them at any moment.

    A. are expected          B. have expected

    C. are expecting         D. will expect

“It’s twelve o’clock, I think I must be off now.” “Oh, really？ I ______ it at all.”

    A. don’t realize                 B. haven’t realized

    C. didn’t realize                D. hadn’t realized

. In the market, vegetables are sold by _______ kilogram, I mean, by _______ weight.

A. the; 不填   B.不填; 不填

C. the; the      D.不填；the

 “Have you seen _____ pen? I left it here this morning.” “Is it _____ black one? I found it in the corner.”

A. a, the  B. the, the

C. a, a     D. the, a

We‘ve missed the train！” “_____, there’ll be another in ten minutes.”

    A. All right                      B. Not at all

    C. Never mind                     D. Don’t mention it

I found the island a wonderful place for our experiments _______ the hot weather.

A. besides       B. except for

C. except D. except that

The writer is not satisfied with _______ buses are too crowded.

A. that    B. which

C. what   D. the fact that

I can’t answer for ________ that the boy is honest.

A. it B. me

C. which D. them