用所给单词的适当形式填空。

1. Students are supposed              (arrive) at school on time.

2. —Thank you for your kind               (invite).

    —It's a pleasure.

3. What should you do when you meet for the             ( one) time?

4. I guess you should             (ask) what you were supposed to wear.

5. His bike is            (difference) from mine.

[问题2] 该网络的物理拓扑结构是什么类型