I have a bag with books in it.(“in it” 不能省略)?

I have a bag with books in it.(“in it” 不能省略)? i have a bag with books in it I have a bag with books in it .这里的in it 做什么成分? I have a bag in blue.I like it a (l ).I go to school with it a small bag with monkey in it There is a hole in our bag I know.I'm going to have it ____ a small bag with money in it 的意思 a small bag with money in it是什么物品 a small bag with money in it的意思 Oh,I can put my books in the ( ),it's a nice bag.的( )可以怎么填 I have many books in my bag 同义句：I have___ ___books in my bag I have five books in the bag.同义句