6. He( )his previous best performance in the 1000 meters.
A. improves
B. improves on
C. betters
D. proves
7. I( )to interrupt a man when he’s busy working.
A. envy
B. hate
C. admire
D. improve
8. he was astonished( )what he found.
A. at
B. to
C. for
D. on
9. They made no effort to hide their amusement( )I produced a packet of sweets from my pocket.
A. whatever
B. wherever
C. whoever
D. whenever
10. I had hoped to get $1000 for my old car but had to( )a lot less.
A. settle down
B. settle in
C. settle for
D. settle on

参考答案：6. B7. B8. A9. D10. C
6. better和improve均有"提高"、"改善"之意，better主要指改善地位或经济状况；improve指提高文化水平。
8. astonish后接动词时常用不定式。be astonished at 对……很惊讶
10. settle down 定居；
settle in 在新居安定下来；
settle for 勉强认可；
settle on 选定，决定。