—What happened to the young trees we planted last week?
—The trees _ well, but I_ them．
A. might grow; hadn't watered
B. needn't have grown; didn't water
C. would have grown; didn't water
D. would grow; hadn't watered
网友回答
A. might grow; hadn't watered
B. needn't have grown; didn't water
(答案→)C. would have grown; didn't water
D. would grow; hadn't watered
解析：考查虚拟语气和时态的用法。句意：去年春天种树的时候发生了什么事？这些书本可以长的很好，但是他们没有细心照料。would have done 是对过去事情的虚拟，本可以做却没做，第二空根据后面使用了转折but 来看。表示事实上没有浇水，是过去的事实，用一般过去式，选C。