题目内容：

1.The old man has two daughters,_________are doctors.
A.both of them B.both of whom
C.both who D.they both
该选择什么?

优质解答

应选B,记住：of是介词后接人称代词的宾格.我给你举一个简单的例子你就会明白了.例如.Some of them are playing basketball.=We are both playing basketball.
祝你越学越好!