Coal
Coal i o commonly ued in life that we eldom notice it. We burn coal everyday to heat food and water. The firt locomative wa driven by burning coal. In winter we feel a pecial need for coal. The coal give u fire, light, heat and warmth. Indutry cannot operate withoutcml, therefore,mai i9 called the food lot indutry.
Coal i not o treaured a gold. Gold i made into hining ornament for the neck of heroe and heroine. Coal i hining in it own way. It burn ilently for the benefit of all. In a ene it i black gold.
Coal underwent great change before it became the bright, brittle, black ubtance which we now ue. During ancient time, when the earth enjoyed a very warm and moit climate, the land wa covered with large foret and big plant. A time went on, the ground changed and began to ink. Thee enormou quantitie oftree and vegetable matter were covered by a depoit of and and clay. Thi layer of and and clay preed upon the layer beneath and prevented the contact with air. Thee tree and plant uccummed to the preure and changed their appearance.
Generation after generation, a the ground kept gradually inking, another layer of and and clay wa depoited above the layer already formed. A great preure wa thu exerted and the peat wa changed into the black and brittle ubtance which i known a coal.WWw.hAOZuowEn.com
From the formation of coal, I ee that the coal ba the ame character a the pine tree in winter. The pine remain green when they are covered with now. The coal remain of ervice to mankind after being burted underground for year and year.
煤
煤在生活中用得如此普遍，以至于我们很少注意到它。我们每天烧煤做饭、烧水。第l辆火车是用燃煤的方法开动的。冬天我们特别需要煤。煤给我们火、光、热和温暖。工业离不开煤，因此，煤被称为工业的食粮。
煤不像金子那么贵重，金子用来做装饰品，挂在英雄的脖子上，然而煤以它自己的方式闪光。为了大家的利益，它无声地燃烧。在某种意义上，煤是黑色的金子。
煤经历了巨大的变化才变成亮、脆而黑的物质供我们使用。在古代，地球经历了温暖、潮湿的气候，土地被大片的森林和高大的植物所覆盖。随着时间的流逝，地面下陷，大量的树木、植物类的物质受到泥沙的覆盖。这层泥沙压在植物层之上，使它不能与空气接触。这些树木、植物由于受到压力而变形。
经历了多少代又多少代，随着地面不断地渐渐下陷，又有另一层泥沙覆盖在已经形成的泥沙层上，因而产生巨大的压力，泥炭便变成又黑又脆而被称作煤的物质。
从煤的形成中可以看出，煤具有冬天里松树的性格。松树被雪覆盖时，仍然保持碧绿；煤被埋在地下多少年又多少年，仍然在为人类服务。