阅读下面材料,从每题所给的A、B、C、D四个选项中选出最佳选项。
American schools must obey the classroom rules. Here are some of them.
If the teacher asks you a question, you should answer it at once. If you do not understand the question, you can put up your hand and ask the teacher to say it again.
You must not be absent (缺席 ) on a test day. If you are seriously ill, let the teacher know. If your teacher allows make-up tests, you'd better take the test within one or two days after you return to class.
It is rude(不礼貌的)to be late. If you are late, you should come into the classroom and go to your seat quickly. In the US it is not necessary to knock before you enter the classroom.
In America, you should call your teacher by his or her last name, not "teacher". Also you should use Mr. Miss, Ms or Mrs before the last name, such as Mrs Smith or Mr Jones.
In the US, it is impolite to eat, drink or chew gum (口香糖 ) during class. Don't do these until(直到)the break.