eat as many vegetables as pssible ,for they are rich ___ iron

问题描述:

eat as many vegetables as pssible ,for they are rich ___ iron

of
(be rich of sth)

of.
be rich of sth.=富含。。
固定搭配,记住就好
尽量多的吃蔬菜,因为它们富含铁元素。

OF,be rich of.固定词组,富含.的意思.
这句话的意思就是“请吃尽量多的蔬菜,因为富含铁元素“

of