氮化铝（AlN）具有耐高温、抗冲击、导热性好等优良性质，能在许多工业领域被应用．工业将氧化铝、氮气和碳在一定条件下反应制得AlN和CO．
（1）氮化铝陶瓷属于 _________ ．（填字母A．金属材料 B．无机非金属材料）
（2）制AlN的化学反应方程式 _________ ．
（3）铝、氧在地壳中的含量居所有元素的第 _________ 位和 _________ 位．铝元素摄入过多对人体有害，请给大家提一条减少生活中铝元素摄入的合理化建议 _________ ．
（1）B；
（2）Al2O3+N2+3C==2AlN+3CO；
（3）三；一；少吃用明矾加工的食品；少用铝制容器装食品；或少使用明矾（十二水合硫酸铝钾）净水；少用铝制炊具等．
| 阅读下面短文，选择最佳答案。 |
| Students learn their lessons in class. In class teachers teach them. Students sit in the classroom listening to the teacher. This is a way of learning. Is this the only way for students to learn something? Of course not. There is another way to learn. It is that students can teach themselves. For example, if you can't remember something when you are doing your homework, you can look at your book to find the answer. This is a way to teach yourself. And it is not a difficult thing. We can do this at any place and at any time. How do you teach yourself? The first thing you must do is reading. Read something you are interested in, or you have to read. The second is that you must ask yourself questions. The question is something you don't understand, or you want to know more about. You can write down these questions. A clever student is usually good at questions. The third is to answer the question yourself by thinking hard, by reading the text or other books, and sometimes by asking other people. This is the way of teaching yourself. And you must do this all by yourself. If you keep doing like this for a long time, you are sure to succeed (成功) in your study. |
| 1．Listening to the teacher is ______ for the students to learn something. |
[ ] |
| A．not a way B．the best way C．not the only way |
| 2．Which of the following is RIGHT? |
[ ] |
| A．A student can teach himself but he doesn't like to. B．It is a bad way to learn from the teacher. C．A student can learn to teach himself if he wants to. |
| 3．In teaching yourself, the first thing you must do is ______. |
[ ] |
| A．asking B．answering C．reading |
| 4．A clever student usually likes ______. |
[ ] |
| A．asking questions B．finding answers C．answering questions |
| 5．If you want to succeed, you'd better learn ______. |
[ ] |
| A．how to teach yourself B．how to teach others C．to read and write carefully |