Different types of natural resources .
不同类型的自然资源。
Earth has many natural resources.
地球有许多自然资源。
We use them in many ways.
我们在许多方面使用它们。
A tree is a natural resource.
树是一种自然资源。
We use wood to make goods like furniture.
我们用木材制造像家具一样的商品。
A tree can be replaced.
一棵树可以被替换。
If we cut down the tree, another one can grow.
如果我们砍掉这棵树，另一棵还能生长。
But it takes many years.
但这需要很多年。
Coal is a natural resource.
煤炭是一种自然资源。
We use coal to make electricity.
我们用煤发电。
An ore is another natural resource.
矿石是另一种自然资源。
Ores contain metal.
矿石含有金属。
We use metal for making many goods.
我们用金属制造许多商品。
Some natural resources, like coal and ore, take millions of years to be made.
一些自然资源，如煤和矿石，需要数百万年才能制造出来。
Their supply is limited.
他们的供应是有限的。
Once used, they cannot be replaced quickly.
一旦使用，就无法快速更换。
We are using these resources very quickly these days.
如今，我们正在快速使用这些资源。
We need to reduce the amount of natural resources we use.
我们需要减少自然资源的使用量。
They need to be conserved.
它们需要被保护起来。
If all the coal and ore are used up, electricity and goods will have to be made in other ways.
如果所有的煤和矿石都用完了，电力和商品将不得不以其他方式制造。