Parents love their children with a devotion ______ no return.

问题描述:

Parents love their children with a devotion ______ no return.
15.Parents love their children with a devotion _______ no return.
A.which they ask for B.which they ask
C.for which they ask for D.for which they ask
为什么选C,不是D.
那里面两个for分别是什么作用啊

从句改成正常句式相当于
ask for no return for which
no return 是ask for的对象,第二个for做“由于”讲
因为which,她们ask for no return