阅读下面短文,从短文后所给的A、B、C三个选项中选出能填入相应空白处的最佳选项。
Do you know what American students do in class? Here are 1 . American classroom customs.
If the teacher asks you a question, you should give the 2 immediately. If you do not understand the question, you should 3 you hand and ask the teacher to repeat the question. If you do not know the answer, it is all right 4 the teacher that you do not know.
Be 5 time! It is 6 to be late. If you are late, be sure to enter the classroom 7 .Have your books and papers out of your bag before you come 8 the classroom. Then go to your seat and sit quietly. In America, it is not necessary to knock 9 you enter the classroom. Most teachers will give you a low grade if you are often late.
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 10. This is polite. The teacher will tell you the title that he or she likes.