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
B: is being polluted
C: has been polluted
D: have been polluted
正确答案是：
同类题型
ty center, we saw a stonestatue of about 10 meters in height
She looks very happy. She ____have passed the exam.—I guess so. It’s not difficult after all.
The people who have ________the event offered special information about the event.
He is always helping people without expecting anything________[ ]