Teaching goals 教学目标
1. Target language 目标语言
a. 重点词汇
expand, contract, conclusion, method, liquid, solid, iron, mixture, oxygen, electricity, aim, equipment, react, result, steam, substance, boil, float, form, dissolve, rust
b. 重点句式
It is hard to think of a world without metals. P44
It is important to know how they react with different substances, for example, water and oxygen. P44
This makes sure there is no air in the water. P45
