单选题
The water will be further polluted unless some measures______
A、
will be taken
B、
are taken
C、
were taken
D、
had been taken
【正确答案】
B
【答案解析】
[解析] 考查时态。表示一种假定的情况时，主句如果用一般将来时态，从句则用一般现在时态。
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