题目内容：

More car pools should be formed in order to have fewer cars on the road and to use less gasoline.
请解释should be 是什么语法结构,为什么句子用should be 结构

优质解答

从主语 car pools 来判断 后面的动作应该不是car pools 主动去实施的 所以要用被动语态 should be formed