He threw the book out (of) the window.中为什么out后不能加of?

He threw the book out (of) the window.中为什么out后不能加of? 英语：he threw his____ bag out of the window quickl. I looked out of the window中,OUT OF为什么加OF呢?有什么意义呢? 翻译out of the window out of the window是什么意思 look out of the window I looked out of the window.window 为什么不加s? window,he,the,often,out,of,in,looks,classl He is leaning_____ ______ the window.A.of out B.out in C.out the sun (shine)out of the window ()(not look)out of the window填什么?为什么? _the leftover food,Tom threw it out of the doorway