英國學(xué)生科學(xué)讀本 Lesson 32 一塊軟木(1)
第32課 一塊軟木
Corks are so cheap and so common, that every child who reads this Lesson can get a cork to handle and to look at. Let us try with a pen-holder to keep a cork down at the bottom of a glass of water. It is very hard todo this; for the cork is very much lighter than its bulk of water, and so it is always trying to rise to thetop.
軟木很便宜, 很常見。讀到這一課的小朋友, 人人都可以把一塊軟木塞拿在手上, 好好看看。咱們試試, 用一支筆桿子把軟木塞按到一杯水底下。很難把軟木塞按住, 因?yàn)檐浤救人@么大體積的水輕得多, 所以總是要往水面上浮。
Men who go out in life-boats wear canvasbelts filled with pieces of cork. If the boat should be upset, the cork is so light that it would help the men to float , and save them from drowning.
救生艇上的救生員, 都穿著一種帆布帶子, 里面盛滿了軟木塊兒。要是船萬一翻了, 軟木非常輕, 可以讓人浮起來, 不讓人淹死。
Squeeze a cork between your fingers. You can easily compress it, or make it smaller. But when you take your fingers away, the cork springs out to its old size and shape. Things that do this are called elastic.
用兩個(gè)手指擠一下軟木, 可以很容易地壓縮這塊軟木, 讓它變小。可是, 一放開手指, 軟木就彈回了原來的大小和形狀。有這種性質(zhì)的東西叫做“彈性物體”。
Because cork is elastic, it makes good stoppers for bottles. The cork ought to be just a little larger than the neck of the bottle. We force the cork into the neck of the bottle, and it presses against the sides of it, and fits it exactly.
因?yàn)檐浤臼怯袕椥缘? 所以很適合做瓶塞子。軟木塞應(yīng)該只比瓶頸大一點(diǎn)兒, 我們把軟木塞用力塞到瓶頸里面, 軟木塞就擠在了瓶頸的壁上, 尺寸剛剛好。
But what is cork? Cork is the outer bark of a kind of oak-tree, which grows in the south of Europe. It is an evergreen oak— that is, it is always covered with green leaves. It grows to a height of thirty or forty feet.
但是, 軟木究竟是什么東西呢? 軟木是一種櫟樹的樹皮, 這種樹長在歐洲南部, 是一種常綠喬木, 也就是一直長著綠葉子的樹, 能長到30–40英尺高。
