who is缩写就是：Whos 扩展： whose 的意思是“谁的” whos的意思是“谁是",也是who is 的缩写
例如：
It's my dog.划线提问my,应该用whose.Whose dog it is?
He is my firend LiMing.划线提问my friend LiMing.应该用：who's.Who' he?
