单项选择题

Once water pollution（） , it would be rather difficult to put it under control.

A. has done
B. does
C. did
D. is done

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单项选择题
What does the woman mean（）

A. She’d like to go.
B. She wants to finish her paper.
C. She can’t go.
D. She doesn’t want to finish her paper.
单项选择题
how many people will come according to the dialogue（）

A. 2.
B. 4.
C. 6.
D. 8.
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