817.Yao Ming is very famous now. However, his basketball career ______ many years of hard work.

A.took on

B.took off

C.took up

D.took out

818.To the great disappointment of the poor workers, a great part of their wages were _____ by the boss for no good reason.

A.kept away

B.kept off

C.kept up

D.kept back

817.答案是B;

take on呈现，采纳，承担，从事;take off起飞，匆匆离去，脱下，事业腾飞;take up占 据，占（时间、空间），开始从事;take out取出，拿出。

818.答案是D;

keep away(from)使远离;keep off避开，不接近;keep up保持，不低落，持续，继续;keep back扣除，保留，隐瞒。