It is good manners to eat up is left in your plate.A. thatB. whatC. whichD. all

问题补充：

It is good manners to eat up is left in your plate.

A. that

B. what

C. which

D. all

答案：

A. that

(答案→)B. what

C. which

D. all

解析：句意为：吃完你盘子里的东西是一个有礼貌的行为。用在eat up之后是一个宾语从句，由此可排除D；that引导宾语从句，不作宾从的任何成分，故排除A; what which引导宾从，且也作句子的主语，但which必须有选择范围。