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
Look at the trouble I am in! If only I _____ your advice.[ ]
does it take from your home to your school — It takes about twenty minutes by bike.
The teacher often tells us ____________.
The river have ________, so they will have to spend much money irrigating(灌溉) the crops.
Do your parents often watch TV at home— No. We _______ like reading books.