十万火急~On the way to school I saw some trees.Their leaves were eaten up by insects.

题目

十万火急~On the way to school I saw some trees.Their leaves were eaten up by insects.
为何合成带定语从句的复合句时只能用whose而不能用which?
改写后的句子是什么?

答案

On the way to school I saw some trees whose leaves were eaten up by insects.或On the way to school I saw some trees,of which the leaves were eaten up by insects.