为什么用of

China has hundreds of islands,____we all know.
A.in which B.at which C.of which D.which
这句话什么意思啊?不可以用which么

为什么用of呢？ can you take photos of me?句中的of是什么意思?为什么用of? of 为什么用在此处 为什么用which 不用of which Aunt Lee will arrive in Shandong on the afternoon of March 8.为什么用of？这里的of是什么意思？ method of doing the thing 这一用法中为什么要用of,而不是from? the police carried out a through search of the building.为什么用of不用in. 为什么用men of this kind而不用man of this kind The population of China is larger than( that) of Indian.这里为什么用that 为什么要加个worth of