Sources of Heat.
Heat is energy.
Heat comes from many sources.
热量来自许多来源。
Heat moves from warmer areas to cooler areas.
热量从温暖的地区转移到寒冷的地区。
If you rub your hands together, they get warm because of friction.
如果你把双手搓在一起，它们会因为摩擦而变热。
Friction is a source of heat.
摩擦是热源。
Light from the sun is energy.
来自太阳的光是能量。
It heats things and makes them warm.
它加热物体并使其变热。
A light bulb uses electricity to create light.
灯泡用电发光。
Heat is also created.
热量也被创造出来。
When natural gas burns, heat is created.
天然气燃烧时会产生热量。
We use natural gas to heat things like water.
我们用天然气来加热水之类的东西。
Heat can change matter.
热可以改变物质。
If you heat an ice cube, it will melt.
如果你加热冰块，它就会融化。
It goes from being a solid to a liquid.
它从固体变成液体。
Heat can cook food.
热可以煮熟食物。
We cook food in a metal pot on a stove.
我们在炉子上的金属锅里做饭。
Metals are good conductors of heat.
金属是热的良导体。
Heat moves from the stove to the food easily.
热量很容易从炉子转移到食物上。
Plastic is not a good conductor of heat.
塑料不是热的良导体。
That is why most pots have a plastic handle.
这就是为什么大多数罐子都有一个塑料把手。