On the top of the hill we may see that the clouds ------A.are building up B.are built up C.are building D.are built请写出理由,

问题描述:

On the top of the hill we may see that the clouds ------
A.are building up B.are built up
C.are building D.are built
请写出理由,

选D被动语态

A哦.
clouds are building up 就是描写云在聚集,与前面的that在一起做从句,是see的宾语.