surprised me most was such a little boy of seven could play the violin so well.A. That..

问题补充：

surprised me most was such a little boy of seven could play the violin so well.

A. That...what

B. What...that

C. That...which

D. What...which

答案：

A. That...what

(答案→)B. What...that

C. That...which

D. What...which

解析：考查名词性从句。What引导主语从句What surprised me most，并在句中做主语。That引导表语从句that such a little boy of seven could play the violin so well.因为这个表语从句很完整，所以使用that引导，that没有任何意思，只起连接作用。