[音频]Petroleum is a very __1___ mineral. It gives us heat and light. It also gives us power for our cars, planes, and ships, it gives us power for machines of __2___. How was petroleum created？ Scientists __3___ petroleum was formed from the remains of _____4_____. Remains are what is left after a plant or animals has died. These plants and animals lived and died _____5____ years ago. What exactly is petroleum? Petroleum is a mineral that is a mixture of hydrocarbons. It is an oily liquid which may be __6__, green, or black ____7____. The word petroleum ____8____ Latin and Greek. It means rock oil. Crude oil petroleum that comes directly from deep in the ground. it is then taken to a refinery. A refinery is a kind of factory with equipment to refine oil. At a refinery the crude oil is purified and separated into its____9___. From the refined petroleum we obtain important products such as gasoline, kerosene, fertilizers, detergents, plastics, drugsand perfumes. These are just ___10___ of the thousands of useful products we get from this valuable mineral--- petroleum.