Metal
金属
What happens if there is no metal in the world?
如果世界上没有了金属会发生什么?
We can't build any buildings.
我们就盖不了楼房了。
We can't make computers, cars and machines either.
我们也制造不了电脑、汽车和机器。
Hammers, nuts, nails, door locks and keys are also made of metal.
锤子、螺帽、钉子、门锁和钥匙也都是用金属制成的。
We can't use a electricity without metal, because electric wires are made of metal too.
没有了金属我们就用不了电,因为电线也是用金属制成的。
Where do we find metals?
我们在哪找到各种金属?
Metals are usually found deep in rocks.
通常在岩石深处找到各种金属。
Some metals like aluminum, iron and titanium are easily found, so they are cheap.
一些金属如铝、铁和钛很容易找到,所以它们很廉价。
However, some metals like gold are very rare and expensive.
然而,一些金属如黄金却非常稀少和昂贵。