Who is the singer you like best?A. thatB. whoC. whomD. which

问题补充：

Who is the singer you like best?

A. that

B. who

C. whom

D. which

答案：

(答案→)A. that

B. who

C. whom

D. which

解析：以who, which 引导的句子，定语从句只能用that。