We bought __________boxes of such apples yesterday.

问题描述:

We bought __________boxes of such apples yesterday.
A three dozen B three dozens C three dozens of D three dozen of为什么是A?

首先排除B
boxes已经是复数 dozen不用再加s
同理排除C
D的话因为已经有box dozen不需要加of
加of的是dozens of这个词组 前面不需要加数字