饱和差
参考答案：
同温度下的饱和水汽压与实际水汽压之差。
饱和差随水汽含量的增大而减小，随温度的升高而增大。
人体的各种体育运动靠运动系统就能完成．______．
用 electric, electricity, electrical及 electronic填空
1.Turn off the computer when you don't use it. Don't waste __ .
2. His father is an engineer.
3. Do you know who invented the light?
4. Nowadays most young people prefer to send mails rather than write letters.
