Trees are useful to man mainly in three ways,the most important of which is that they

问题描述:

Trees are useful to man mainly in three ways,the most important of which is that they
接can protect ______ from droughts (干旱) and floods.
A.it B.itself C.himself D.him
答案为什么是D

这里的him是指代man 人类
而不是指树木.句以理解为 树木最主要的用处在于它能保护人类免受干旱和洪灾.