简述订立合同必须遵守的基本原则。
参考答案：
（1）主体合格
（2）遵守法律
（3）平等互利、协商一致的原则
（4）采用书面形式
根据句意及首字母填写单词。
1. Our English teacher's p_____ is very nice and clear. We can understand her well.
2. Boys and girls may behave d_____ on the same occasion.
3. It doesn't m_____ that you broke the window. Be careful next time.
4. You made several m _____ in spelling. Pay more attention to your spelling.
5. Careful planning is the s_____ of success.
小儿体重在1～10岁时每年增长约（）。
A.1kg
B.2kg
C.3kg
D.4kg
E.5kg
