题目

完形填空 One Friday morning Chen Hua gets up late. When he gets to the door of the classroom, Mr. Gao, his math teacher says, You are1again. Now how many times are you late this week? Three times. Why are you late2class? Because I get up late. Why don't you go to bed3? asks the teacher. It isn't my fault(过错), Mr. Gao. The TV play is over4about eleven. answers Chen Hua. Now, please5me your homework. says the teacher. I'm sorry, I can't do it. Why don't you do it? asks the teacher. Because the first part of the homework is6easy. I don't think I need to do it. The 如图所示，甲、乙两个门窗紧闭的房间里各有一位同学，乙房间的玻璃是双层的，中间抽成真空．（1）甲、乙两个房间的同学都能看见树上的小鸟，这是为什么？（2）但乙房间的同学听不到小鸟的“歌唱”，又是为什么？