The teacher came in,with glasses on his nose.为什么这句的 on his nose 不可省略啊?

Keep ( ),the teacher came in ( ）（quiet) The students stopped______(talk)when the teacher came in. When the teacher came in ,the students stopped ______(talk ) The students------(stop)talking when the teacher came in The children stopped (talk) -----------as the teacher came in The students________(chat)until the teacher came in. The students all stood up ____ the teacher came in. 是 in came the teacher 还是 in the teacher came如果是 in came the teacher 那么为什有 Out he rushed 而不是 Out rushed he? they,what,doing,teacher,the,in,came,were,when When the teacher came in,we __（talk） （the teacher came in when I was reading)是否正确 _________ __________ you _______ when the teacher came in? I was reading books until the teacher came in. We all stoped____(talk) when the teacher came in. Who_____you____(talk) with when the teacher came in Every student became q______when the teacher came in The teacher came in.The class began at once.合并为一句The teacher came in.The class began at once.变为 The class began ______ ______ ______ the teacher came in. 急求解析Which of the following sentences is correct?A.In the teacher came B.In did come the teacher C.In did the teacher come D.in came the teacher应该选哪个,为什么是错的!