2 . —May I go and play with Dick this afternoon, Mum?
—No, you can’t go out _______ your work is being done.

A．before

B．until

C．as

D．the moment

3 . — The water was left running all night long.
— Yes. It seemed that John       . He was the last one to leave the lab.

A．was to be blamed	B．was to blame
C．had been blamed	D．should be blamed

5 . You have three layers of skin which act as a ______(屏障) against disease, poisons and the sun’s harmful rays. (根据汉语提示单词拼写)

6 . We shouldn’t complain about being poor, because many families are much ______ after the big earthquake.

A．better off	B．worse off
C．well off	D．badly off

7 . —I wonder how much you charge for your services.
—The first two are free, _______ the third costs ＄30.

A．while

B．until

C．when

D．before

8 . He was _______(ban) from taking part in matches for three months after failing a doping test in the previous week.

9 . He didn’t blame her father’s death _______anyone.(用适当的词填空)

10 . We'll never forget those who _______ (bleed) in the wars for the revolution of China.