For many years,people _____ electric cars.However,making them has been more difficult than predicted.[ ]A.had dreamed of B.have dreamed of C.dreamed of D.dream of为什么不能用过去完成时

问题描述:

For many years,people _____ electric cars.Howe
ver,making them has been more difficult than predicted.
[ ]
A.had dreamed of
B.have dreamed of
C.dreamed of
D.dream of
为什么不能用过去完成时