9.     (worry)    too    much about your child may cause mental illness.

8. Small steps can be taken_(reduce)  pollution    in our daily lives.

7.    — I’d like to add a little bit more sugar to the coffee.

—No need. I_(put)   enough.

6.    — Dear! Why didn’t you answer my telephone?

—Sorry! I_(attend)  an important meeting then. My mobile phone was left in my    office.

5. Nearly half of the village which has been there for nearly one thousand years_(bum) down by the great fire unless (除非）further actions are taken.

4.    一 A report says the new virus (病毒）has caused  a serious  problem    in some Chinese provinces.

—It also says that it _(stop) and _(clear) at last.

3.    一 Why not look at page 20 of your English book?

—Ah, here the key is! I wonder why I_ (not  know)  this.

2.    — Which is easier to catch fire, gas or oil?

—I was told long ago that oil_(catch)   fire   easily. But what about gas? I don’t know.

1.    There is no one in the lab. Everybody was seen_ (go)  out.

(    )    10. We all think we’ll have fun_volleyball    at the beach on sunny days.

A. playing    B.    to play    C.    played    D.    to be playing