David is such a good boy all the teachers like.A. thatB. whoC. asD. whom

问题补充：

David is such a good boy all the teachers like.

A. that

B. who

C. as

D. whom

答案：

A. that

B. who

(答案→)C. as

D. whom

解析： as 用作关系代词，用以引导定语从句，修饰其前的名词 boy，同时 as 在定语从句中用作动词 like 的宾语，句意为“所有老师都喜欢的一位好男孩”。