题目内容：

Shirley had to buy ____ these CDs becuase she didn't know which one to take.
A all B none C each D both
为什么选A?

优质解答

根据后面的because从句中她不知道买哪个,所以她不得不都买下来.
B.none和C each不可以后面直接跟名词these CDs,需要先加of.所以排除B和C.
D项both不可以和these搭配.

追问：

each CDs 可以这么说吧? each后不能接these吗？

追答：

each CD 或者是each of these CDs