煤是形成的高中英语作文.doc

煤是形成的高中英语作文 煤是怎么形成的高中英语作文 　　Coal is a kind of important industrial material which is chiefly used as fuel.lt is very valuable in the industrial world.In China,coal mines are largely found in the northwest part of the country. 　　Coal nnderwent many changes before it became the bright and brittle substance Which We now use.During ancient times,when the earth enjoyed a very warm and wet climate,the land was covered with large forests and big plants.As time went on,the ground changed and began to sink a little.These very large numbers of trees and vegetables received the deposit of sand and clay.This layer of sand and clay pressed upon the layer beneath and prevented it from contacting with air.These trees and plants received the pressure and changed their appearance. 　　Generations after generations,as the ground kept gradually sinking,another layer of sand and clay again deposited above the layers that already formed.A great pressure was thus exerted and the peat was changed into the black and brittle substance which is known as coal. 　　煤是一种重要的工业材料，主要用作燃料。

它在工业世界中非常有价值在中国，煤矿主要发现在该国西北部 　　煤经历了许多变化，才变成了我们现在使用的明亮、脆弱的物质在上古时代，当地球享受非常温暖和潮湿的气候时，土地上覆盖着大面积森林和大型随着时间的.推移，地面改变了，开始下沉了一点 这大量的树木和蔬菜被沙和粘土的沉积物掩埋，这层砂和粘土压在下面的层上，防止它与空气接触 这些树木和植物接受压力并改变了其外观 　　几世纪后，随着地面逐渐下沉，另一层砂和粘土再次积聚在已经形成的层之上因此，它们给下面的土层施加了巨大的压力，于是泥炭变成黑色的脆性物质，称为煤。