广播电视英语短句 第 290 课：找到粘土-2

After a long time, some of the rock changes to clay. 经过很长时间之后，其中一些岩石就演变成了粘土。

Clay is important because it is used around the world to make containers of all kinds. 粘土能在世界各地范围内制成各类容器，所以它是很重要的。

Potters add water to soften the clay. This makes it easier to form into shapes by hand or by machine. 制陶工人通过加水的方法来软化粘土，这使得不论手工处理还是机械操作都能更容易地使其成型。

Then it is fired in an extremely hot stove. 然后将它置于一个非常热的火炉内进行加热处理。

The result is a container with a hard surface that will last for many years. 完工后就能形成一个能使用很多年的并且拥有坚硬表面的容器。