根据磁导率不同，物质可按磁性不同分为三大类，例如：铝、铬、锰等属于（）；铁、镍、钻等属于（）物质；银、铜、汞等属于（）
参考答案：顺磁性；铁磁性；逆磁性
根据句意，写出括号内所给单词的适当形式
1. After drinking the cup of coffee, he felt even _________. (sleep)
2. Look, the children are trying to catch _________ (butterfly) on the flowers.
3. I have got toothache, so I must go to the ______________. (dentist)
4. We think more public activities will help change his ____________ life. (active)
创建文明城市对民航机场的要求是什么？
