定语从句的题.我这句话根本读不懂啊

We don't know the precise use______Google makes of Chinese famous works,but its scanning of them without permission is illegal.
A which B how C when D what
主句主语：We
主句谓语:don't know
主句宾语：the precise use
引导定语从句关系代词（which)
定语从句主语：Google
定语从句谓语：makes
定语从句宾语：(前面先行次use,关系代词which充当从句宾语 make use of 短语）
表述转折关系并列连词：but
主语：its scanning of them
状语：without persmission
系动词：is
表语：illegal

We don't know the precise use_______ Google makes of Chinese famous works,but its scanning of them without permission is illegal.
make use of
把use充当先行词，所以，答案用which
定语从句相当于Google makes...