6. Smoking is not good () you because it can affect your health.

A. for B. at C. to D. on (A)

be good at…擅长 be good for… 对。。。有好处

7. Mary’s younger brother, though 6 years old, is very quick () doing calculations.

A. of B. on C. in D. by (C)

be quick in(at) doing… 敏于做。。。

8. The teacher will ask you to account () your absence from his class yesterday.

A. for B. at C. n D. of (A)

account for 解释(原因)

9. The flyover at the crossing on the 4th Ring Road is now () construction.

A. under B. at C. in D. with (A)

under 在。。。之中 在。。。情况下

10. People’s complaints the bad food were soon taken consideration by the government. ()

A. of…into B. for…on C. of…for D. with…against (A)

complain v. complaint n.

complain to sb. about(of)… 就。。。向。。。投诉 take into consideration 把。。。考虑在内