根据句意及汉语提示完成下列句子

1. Grace____   ____  （必须）wear her____  （制服）to school every day.  

2. My father bought a pair of____   ____  （运动鞋）for me yesterday.

3. We have three____   ____  （体育课）every week.  

4. 1t is warm in the room but cold____  （外面）.  

5. What are the____  （规定）at your school?

下列说法中正确的是

A．不饱和溶液变为饱和溶液溶质质量分数一定变大

B．饱和溶液一定为浓溶液，不饱和溶液一定为稀溶液

C．物质的溶解能力只受温度影响

D．在条件不变时，向KNO₃饱和溶液中加入KNO₃晶体，KNO₃晶体质量不再减少