—WhydoestheLakesmellterrible? —Becauselargequantitieso...

问题详情：

 —Why does the Lake smell terrible?

 —Because large quantities of water_________.

   A. have polluted                              B. is being polluted 

   C. has been polluted                        D. have been polluted

【回答】

D

知识点：现在完成时及其被动式

题型：选择题