We mustn't throw dirty things into the rivers so that the dirty things can be prevented from________the water．A.polluteB.pollutingC.to polluteD.pollutiom
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B解析分析：prevent sb(from)doing sth(阻止某人做某事)等于stop sb(from)doing sth，from在主动语态中可以省略，但如果是被动语态，from则不能省略。