on the wall hangs the puctures,whose cover is blue

问题描述:

on the wall hangs the puctures,whose cover is blue
此处which,of which为什么不对

which 只是一个代词,没实际意义,whose 指代这些图片的封面,且whose 在此处还充当形容词,修饰后面那个名词,而which和of which都没这个功能