| A.Microscopic organisms that live in mud produce crude oil and natural gas. |
| B.Large amounts of oxygen are needed for petroleum formation to begin. |
| C.Petroleum is formed when organic material in sediments combines with decaying organisms. |
| D.Petroleum formation appears to begin in marine sediments where organic matter exists. |
| A.More petroleum is extracted from the sea than from land. |
| B.Drilling for oil requires huge financial investments. |
| C.The global demand for oil has been increasing over the years. |
| D.The North Slope of Alaska has substantial amounts of oil. |
| A.The formation, processing and exploration of petroleum |
| B.The specific techniques involved in oil exploration. |
| C.The changing relationships between countries. |
| D.The future intense situation in oil product markets. |
| A.Available exploration techniques serve our purpose of exploring oil very well. |
| B.More and more public regions will be further protected from being drilled in the future. |
| C.Countries may suffer from unpleasant relationships for respective benefits in exploring oil. |
| D.Powerful flows of oil is a phenomenon which can be witnessed rarely now. |