单选题All possible means ____ &

问题补充：

单选题Allpossiblemeans____,butnothingcanpreventthebuildings____.A.has tried; from being pulled downB.have tried; from pulling downC.has been tried; from pulling downD.have been tried; from being pulled down

答案：

D解析考察主谓一致和prevent的用法。All means谓语动词用复数形式，prevent……from doing sth,阻止……干某事句意为所有的方法都被尝试过了，但是什么也阻止不了这些建筑物被推倒。