煤-Coal

Coal

Coal is so commonly used in life that we seldom notice it. We burn coal everyday to heat food and water. The first locomative was driven by burning coal. In winter we feel a special need for coal. The coal gives us fire, light, heat and warmth. Industry cannot operate withoutcml, therefore,mai i9 called the food lot industry.

Coal is not so treasured as gold. Gold is made into shining ornaments for the necks of heroes and heroines. Coal is shining in its own way. It burns silently for the benefit of all. In a sense it is black gold.

Coal underwent great changes before it became the bright, brittle, black substance which we now use. During ancient times, when the earth enjoyed a very warm and moist climate, the land was covered with large forests and big plants. As time went on, the ground changed and began to sink. These enormous quantities oftrees and vegetable matter were covered by a deposit of sand and clay. This layer of sand and clay pressed upon the layer beneath and prevented the contact with air. These trees and plants succummed to the pressure and changed their appearance.

Generation after generation, as the ground kept gradually sinking, another layer of sand and clay was deposited above the layers already formed. A great pressure was thus exerted and the peat was changed into the black and brittle substance which is known as coal.

From the formation of coal, I see that the coal bas the same character as the pine trees in winter. The pines remain green when they are covered with snow. The coal remains of service to mankind after being burted underground for years and years.

煤在生活中用得如此普遍,以至於我們很少注意到它。我們每天燒煤做飯、燒水。第l輛火車是用燃煤的方法開動的。冬天我們特別需要煤。煤給我們火、光、熱和溫暖。工業離不開煤,因此,煤被稱為工業的食糧。

煤不像金子那么貴重,金子用來做裝飾品,掛在英雄的脖子上,然而煤以它自己的方式閃光。為了大家的利益,它無聲地燃燒。在某種意義上,煤是黑色的金子。

煤經歷了巨大的變化才變成亮、脆而黑的物質供我們使用。在古代,地球經歷了溫暖、潮濕的氣候,土地被大片的森林和高大的植物所覆蓋。隨著時間的流逝,地面下陷,大量的樹木、植物類的物質受到泥沙的覆蓋。這層泥沙壓在植物層之上,使它不能與空氣接觸。這些樹木、植物由於受到壓力而變形。

經歷了多少代又多少代,隨著地面不斷地漸漸下陷,又有另一層泥沙覆蓋在已經形成的泥沙層上,因而產生巨大的壓力,泥炭便變成又黑又脆而被稱作煤的物質。

從煤的形成中可以看出,煤具有冬天裡松樹的性格。松樹被雪覆蓋時,仍然保持碧綠;煤被埋在地下多少年又多少年,仍然在為人類服務。