英國學(xué)生科學(xué)讀本 Lesson 21 一塊石板
第21課 一塊石板
Look at your slate, and see what it is made of. It is a very thin, smooth, grey stone. The pencil with which you write upon it is also a piece of soft slate.
小朋友, 看看你自己寫字用的石板, 了解一下它是什么做的? 這是一塊非常薄、非常光滑的灰色石頭。你在板石上寫字的筆, 也是一塊比較軟的石頭, 叫做板石。
When you rub the soft slate-pencil upon the slate, many little pieces of the pencil are broken off. These tiny pieces form the white marks which you see when you write. They do not stick to the slate, but can easily be rubbed off with a wet sponge.
把軟的板石筆在板石上蹭蹭, 就會(huì)有很多板石筆的碎片掉下來。這些碎片就變成了你寫字的時(shí)候看見的白印子。這些白印子不是黏在板石上的, 用濕海綿很容易就能擦掉。
The slate is not at all like the lump of putty which we made. The putty was soft; we could press it into any shape we pleased. But the slate is hard. However much we squeeze it, we cannot change its shape.
板石, 跟我們以前做過的膩?zhàn)訅K兒, 一點(diǎn)也不像。膩?zhàn)邮呛苘浀? 我們想要什么形狀, 就可以把它捏成什么形狀?？墒前迨苡? 不管怎么使勁兒地?cái)D, 都不能改變它的形狀。
The putty did not break when it fell to the ground; but if we drop a slate, it will break. So we say that the slate is brittle; it snaps or breaks easily.
膩?zhàn)訅K兒掉在地上是不會(huì)碎的, 可要是把一塊板石掉到地上就會(huì)摔碎。所以我們說, 板石很“脆”, 很容易就能折斷、打碎。脆的英語叫brittle.
Like all solids, slate keeps its shape, and it keeps its size too. You cannot change a little slate into a big one, however hard you pull at it to try to stretch it.
跟所有的固體一樣, 板石有固定的形狀, 也有固定的大小。不管怎么拉它, 拽它, 都不能把一塊小板石變成一塊大板石。
Pieces of slate are put on the roofs of houses, to keep out the rain. Water cannot pass through slate. The slater makes two little holes in each slate, and then nails them on to the roof.
板石片也放在屋頂上, 用來擋雨。水是透不過板石的。裝板石的工人在每一塊板石上鉆出兩個(gè)洞, 用釘子把板石固定在屋頂上。
But where do slates come from? 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. A SLATE QUABRY(板石的采石場)
板石是怎么來的呢? 如果你去一趟威爾士、康沃爾郡, 或者蘇格蘭, 你可能會(huì)在山坡上看見一些大洞, 人們管這種大洞叫“采石場”, 英語叫quarry. 在這些地方, 所有的石頭全是板石。
Some men break off great lumps of the rock, and then other men split these lumps into the thin pieces we call slates. We can tell slate from all other rocks by the way it splits into very thin layers.
一些人把板石塊開采出來, 然后另一些人, 把這些大石塊分成我們叫“板石”的細(xì)片。板石跟其他石頭的不同, 就在于它能分成非常薄的石片。
Scrape some slate-pencil into a glass of water. The water looks muddy. The slate itself was once mud at the bottom of the sea. That was a very long time ago; and the slate has been so squeezed and heated inside the earth since then, that it has become hard and stony.
把板石筆擦一些碎屑下來, 讓碎屑落進(jìn)一杯水里, 水看上去就成了泥漿。很久很久以前, 板石就曾經(jīng)是海底的泥, 后來在地球內(nèi)部被擠壓、加熱, 最后變成了硬硬的石頭。
We often find pieces of slate like the one in the picture, full of marks of the shells or of the fishes that lived in the sea long ago. When these creatures died, they sank to the bottom, and were buried in the mud.
我們經(jīng)常會(huì)找到這張圖上這樣的石頭, 上面有很多遠(yuǎn)古生活在海里的貝殼或者魚類的印跡。這些動(dòng)物是在死掉之后, 沉到海底, 被埋在泥中的。
