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】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。