问题描述：
It is uncertain ______ side effect the medicine will bring about,although about two thousand patients have taken it.
A.that
B.what
C.how
D.whether
这题选的是B,如果改成It is uncertain ______ the medicine will bring about side effect...能不能选D?为什么?
A.that
B.what
C.how
D.whether
这题选的是B,如果改成It is uncertain ______ the medicine will bring about side effect...能不能选D?为什么?
问题解答：
我来补答展开全文阅读