The water will be polluted unless some measures .A. will be takenB. are being takenC. are

问题补充：

The water will be polluted unless some measures .

A. will be taken

B. are being taken

C. are taken

D. were taken

答案：

A. will be taken

B. are being taken

(答案→)C. are taken

D. were taken

解析：考察时态及语态。句意：除非采取了一些措施，否则这些水会被污染。句子描述的是一个过去的动作，故用过去时态，measures是take的动作对象，故用被动语态，选D。