______ their service, the workers of the hotel are active in learning English.

A. Improving  B. To improve

C. Improve     D. Having improved

_______ to the top of the hill, and you can see the whole of the town.

A. Get     B. To get

C. Getting      D. Having got

Does the way you thought of _______ the water clean make any sense?

A. making      B. to make

C. how to make      D. having made

All the preparations for the project ______, we’re ready to start.

A. completed  B. have been completed

C. had been completed   D. been completed

The government has _______ the parents to work with teachers in the education of their children.

    A. asked for               B. called for

C. looked forD. paid for

The thief tried to break away from the policeman who ______ him, but failed.

    A. has held                   B. had held

C. was holding                D. would hold

You _____ your turn so you’ll have to wait.

    A. will miss               B. have missed

C. are missing             D. had missed

Dear me！ Just _____ at the time！ I _____ no idea it was so late.

    A. look, have  B. looking, had

    C. look, had  D. looking, have

He         some French while he was away on a business trip in Paris.

A. picked out               B. made up            C. picked up          D. made out

He’s got himself into a dangerous situation _____ he is likely to lose control over the plane.

A. where          B. which      C. while          D. why