单句语法填空

1．She couldn't think what             (give) the children for Christmas.

2．Helen spoke           rapidly that we could not clearly understand her.

3．            was foolish of you to leave school.

4．Even now I find             hard to believe her story.

5．Why not            (try) doing the maths problem in other ways?

6．            this method doesn't work，let's try another.

7．He is            young to go to school.

8．Isn't            a good idea to have a walk around?

9．I find             difficult to talk to you.

10．They have lived in that house             two years ago.

11．He has studied very hard             he came to our school.

12．—It's a long time since I saw my sister.

—Why not            (visit) her?

13．I don't feel            difficult to understand the Special English.

14．            is a pity that he failed to attend my party.

15．English is not too difficult          (learn)．

16．Our teacher explained how             (use) the machine.