--Who sings best in your class?--Mary___________A.did B.doesC.willD.has
问题描述:
--Who sings best in your class?--Mary___________
A.did
B.does
C.will
D.has
答
选B啊
在这里does是助动词,它可以代替实义动词做简短回答,或做省略句.