英语的语法求解

问题描述:

英语的语法求解
only humans and some intelligent animals like apes and dolphins have been shown to recognize that the image in the mirror is of themselves.
其中的"of themselves"是怎么用的,为什么可以接在be动词后面?

the image in the mirror is of themselves.
the image in the mirror is theirs.
of +名词 =名词对应的形容词
of importance=important
of themselves=theirs