mary is good at[ ]the piano A.play b.plays c.playing d.to play

问题描述:

mary is good at[ ]the piano A.play b.plays c.playing d.to play

C
后面跟名词或动名词

be good at后面接名词。所以应该选play的名词形式C。

C
因为前面有AT了

Cbe good at +doing 擅长做某事

选c 因为有个词组叫be good at doing something

C be good at doing 在...方面擅长的意思