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

,– , who is the man– , I don’t know him.

He ____ the apple but couldn’t ____ it. [ ]

I am surprised to hear that Sue and Paul have ______.—- So am I. They seemed very happy together when I last saw them.

10We were anxious _____ news of your safe arrival

_____ the front door is broken, we need to send for someone to repair it.— Let’s ask Jack for help. He does good repair work.