科技英语：石油是怎样形成的

Petrol is formed by ancient organisms. The dead bodies of the living beings in the sea sank to the bottom of the sea. They piled and were separated from the air. Germs decomposing¹ the bodies, along with the high temperature and pressure, the bodies were decomposed² and changed into petrol and natural gas.

　　石油是由古代有机物变来的。在漫长的地质年代里，海洋里繁殖了大量的海洋生物，它们死亡后的遗体随着泥沙一起沉到海底，长年累月地一层层堆积起来，跟外界空气隔绝着，经过细菌的分解，以及地层内的高温、高压作用，生物遗体逐渐分解、转化成石油和天然气。