The pencil with which you write upon it is also a piece of soft slate.

你在写字笔, 也是一块比较软头, 叫。

Every week 30,000 tonnes of slate are gouged out of the mountains.

【gouge】山每个星期都开采出3万吨。

When you rub the soft slate-pencil upon the slate, many little pieces of the pencil are broken off.

把软笔在蹭蹭, 就会有很多笔碎片掉来。

The slate is not at all like the lump of putty which we made.

, 跟我们以前过腻子块儿, 一点也不像。

They do not stick to the slate, but can easily be rubbed off with a wet sponge.

这些白印子不是黏在, 湿海绵很容易就能擦掉。

However much we squeeze it, we cannot change its shape.

可是很硬, 不管怎么使劲儿地挤, 都不能改变它形状。

So we say that the slate is brittle; it snaps or breaks easily.

所以我们说, 很" 脆" , 很容易就能折断、打碎。脆英语叫brittle.

Like all solids, slate keeps its shape, and it keeps its size too.

跟所有固体一样, 有固定形状, 也有固定大小。

The putty did not break when it fell to the ground; but if we drop a slate, it will break.

腻子块儿掉在地是不会碎, 可要是把一块掉到地就会摔碎。

The slater makes two little holes in each slate, and then nails them on to the roof.

装工人在每一块钻出两个洞, 钉子把固定在屋顶。

But where do slates come from?

是怎么来呢?

Pieces of slate are put on the roofs of houses, to keep out the rain. Water cannot pass through slate.

片也放在屋顶, 来挡雨。水是透不过。

You cannot change a little slate into a big one, however hard you pull at it to try to stretch it.

不管怎么拉它, 拽它, 都不能把一块小变成一块大。

We can tell slate from all other rocks by the way it splits into very thin layers.

跟其他头不同, 就在于它能分成非常薄片。

Some men break off great lumps of the rock, and then other men split these lumps into the thin pieces we call slates.

一些人把块开采出来, 然后另一些人, 把这些大块分成我们叫" " 细片。

If you ever go to Wales, or to Cornwall, or to Scotland, you may see great holes in the hill-sides-" quarries, " the men call them- where all the rock or stone is nothing but slate.

如果你去一趟威尔士、康沃尔郡, 或者苏格兰, 你可能会在山坡看见一些大洞, 人们管这种大洞叫" 采场" , 英语叫quarry.在这些地方, 所有头全是。