My brother is very good ping-pong.A. inB. forC. atD. on

问题补充：

My brother is very good ping-pong.

A. in

B. for

C. at

D. on

答案：

A. in

B. for

(答案→)C. at

D. on

解析：is good at是固定搭配，意思是：专长于….。