问题

—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

正确答案是：

同类题型

We have ____ books in our school library.

Take care! Accidents _________ happen along this part of the road.

______ —My name is Alice.

Lucy is in front of Lily and Mike is behind Lily. So we can say Lily is______ Lucy and Mike.

―Our company will organize a trip to Hongkongnext month I ______ my mother there―I’d rather you ____ After all she has just recoveredfrom her illness and she still feels weak