I want to write to Sam,but I don't know ______. 为什么参考答案是D,B为
I want to write to Sam,but I don't know ______. 为什么参考答案是D,B为什么不可以呢?求分析
A.where is his email address
B.where his email address is
C.what pilace is his email address
D.what his email address is