PETROLEUM

作     者：Isaac Asimov 胡君倩 

出 版 物：《大学英语》 (College English)

年 卷 期：1989年第5期

页      面：14-17页

主　　题：PETROLEUM 过去分词短语 

摘      要：Petroleum, like coal, is found in sedimentary rocks, and was probably formed from long-dead living organisms. The rocks in which it is found are almost always of ocean origin and the petroleum-forming organisms must have been ocean creatures rather than trees. Instead of originating in accumulating woody matter, petroleum may be the product of the accumulating fatty matter of ocean organisms