The class in America is almost the same as that in China. But something is different. 1.In America, if the teacher asks you a question but you don't understand, you should put up your hand and ask the teacher to repeat it. If you don't know the answer, it is all right to tell the teacher that you don't know. Then he or she knows what you need to do. 2.You mustn't be absent on a test day. If you are seriously ill, call and let the teacher know you will not be there for the test. If your teacher allows you a make-up test , you should take the test in one or two days after you go back to school. 3.Be on time! It is impossible to be late. If you come in late, be sure to do it quietly. Take your books out of your bag after you enter the room. Then go to your seat and sit down quietly. In the US, you needn't knock before you come into the classroom. 4.If you have to leave during the class, do it quietly, too. There's no need to ask for the teacher's agreement. When a teacher asks you a question but you don't know the answer, you should  _  .
Repeat the question Tell the teacher you don't know Give an answer Put up your hand