i have a bag with books in it

i have a bag with books in it I have a bag with books in it.(“in it” 不能省略)? 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 I have five books in the bag.同义句 I have many books in the bag 同义句 I have two books in the bag 同义句 I have many books in my bag 同义句 I have two books in my bag 的同义词 I have many books in my bag 同义句：I have___ ___books in my bag a small bag with monkey in it I have four books in my bag.对four books 进行提问 （ ）( )you have