Her pet is a ____ dog.

A.middle-size B. middle-sizing C. middle-sizes 　　　 D. middle-sized

By the time he realizes he ____ into a trap, it'll be too late for him to do anything about it.

A.walks B. walked 　C. has walked 　　 D. had walked

Teenagers ____ their health because they play computer games too much.

A.have damaged B. are damaging 　　　　 C. damaged D. will damage

I called Hannah many times yesterday evening, but I couldn't get through. Her brother ____ on the phone all the time!

A.was talking B. has been talking C. has talked D. talked

So far this year we ____ a fall in house prices by between 5 and 10 percent.

A.saw B. see C. had seen 　　　 　　　 D. have seen

--I'm sure Andrew will win the first prize in the final. 　　　

--I think so. He ____ for it for months.

A.is preparing B. was preparing C. had been preparing D. has been preparing

He ____ football regularly for many years when he was young.

A.was playing 　　 B. played C. has played D. had played

We first met on a train in 2000. We both felt immediately that we ____ each other for years.

A.knew B. have known 　C. had known 　　 D. know

--Did you watch the basketball match yesterday? 　　　　　　

--Yes, I did. You know, my brother ____ in the match.

A.is playing 　　　 B. was playing 　 C. has played D. had played

The telephone ____, but by the time I got indoors, it stopped.

A.had rung 　　　　　　 B. was ringing 　 C. rings D. has rung