题目内容：

American schools are quite different from those in China. In America, at the beginning of the term, students must select their courses and teachers first. While in China students usually have no chances to select their courses and teachers.

     Selecting is very important for your grades in America. So at the first term, don’t select too many courses, 1..or you’ll feel very nervous and it may influence your study. Then you have to ask for some teaching plans. There is some information about subjects, time arranging, marks and textbooks. At the same time, you must choose the teachers. Different teachers have different teaching methods. If the teacher is called “killer” by the last grade, many students will give up choosing him. Because this kind of teacher will leave too much homework, too many exams and give too low grades.

    There is another thing after you select the course and the teacher. How to buy textbooks makes each student feel hard. The textbooks in America are very expensive. Each copy is about $30～50. In order to save money, many students buy some used textbooks, and some students usually borrow textbooks from the school library. You must get enough ready before class. In class, discussing is very important. 2.. 老师鼓励你提出问题或展示你自己的观点。They don’t usually ask you to sit well. Instead they allow you to sit or stand everywhere you like. They don’t give you much homework to do. You can learn some knowledge and do exercises by yourself. So in American schools, you must do almost all things yourself.

根据文章内容，补全3.、4.句中所缺单词、短语或句子。

5.At the beginning of the new term, American students have to ask for some teaching plans and get their textbooks ready besides ____________________.

6.The teacher ____________________will always leave too much homework, too many exams and give too low grades.

7.Why do many students in America buy used textbooks ?

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8.请将文中黑体字译成汉语。_________________________________________________________

9.请将划线句子译成英语。___________________________________________________________