由于地面冷热不均而形成的空气环流，称为热力环流，是大气运动最简单的形式．（判断对错）
Many students take the school bus to school every day. Parents think taking the school bus is usually safe (安全的), but sometimes it is dangerous. Some students don't keep the school bus rules. What are the school bus rules?
Arrive at the bus station early.
Wait for (等候) the school bus at the bus station.
Don't run at the bus station.
Don't walk or fight on the bus.
Don't get off (下车) the bus when it goes.
如图所示的电路叫热电偶电路．将铜丝与铁丝的两个接头分别放在温度不同的环境中，例如冰水混合物中和酒精灯的火焰上，此时会发现电流表有读数．课外小组的同学研究了这个电路中电流与温度差的关系，他们得到的数据如下表：
①从数据中，课外小组的同学可以得到这样的结论：两金属接点的温度差越 ____，电流大．
②写出一个这样的热电偶电路可以用在电路中作为 ____使用．它将 ____能转化为 ____能．
A、B两接点间的温度差（℃）
0
1
100
200
300
500
800
1500
1700
电路中的电流（Ma）
64
142
229
417
731
956
1545
1781
