混合性呼吸困难见于（）。

A.急性喉炎

B.气管异物

C.阻塞性肺气肿

D.老年性肺气肿

E.肺不张

用括号中所给词的适当形式填空

1. It takes about 15 minutes               __       __ (walk)  and 5 minutes by bus.

2. What do you think of the___       _ (transport)  in your city?

3. How long did you spend________ (make) the model plane?

4. Thank you very much for__  _____ (invite) me to your birthday party.

5. It's about twenty___       _ (minute)  walk to get there.

6. Don't_______ (worried)  about your mother. I can take good care of her.

7. Don't speak so___        _ (quick).I can't follow you.

8. —How_______ (do) he go to school?

    —He walks to school.

9. Don't speak___        _(China)in English classes.

10.Does Lei Lei need                  ___       _(hand)  in her English homework now?