日前，北京大学校长许智宏公开表示，北大正考虑修改《师德条例》和《学生守则》，拟将“禁止网骂”等内容写入新校规，以此规范北大师生的言行。这告诉我们（  ）
①制订校规是专门用来对付无德学生的
②校规体现了学校和社会的新要求
③校规是最高行为规则
④校规是为了保证我们和谐有序的学习生活环境 

A : What's your favourite invention?

B : Of course computers. They are very important in people's life now.       

A: I like computers, too. I think they will be used even more widely in the future.

B: I agree with you.        

A: I usually use my computer for looking up information reading books and playing games;

B: Do you like shopping online?

A : Yes, of course.       

B: That's true. However, sometimes it isn't safe to buy things online.

A: Yes, so we should be careful when shopping online. What do you like to do with your computer?

B:        

A: You must have many net friends.

B: Sure. I have about 10 friends who are from different countries.

A: