Geologists, scientists who study rocks, indicate the likely places to the oil drillers. In some cases oil comes out of the ground without any drilling at all and has been used for hundreds of years. In the island of Trinidad the oil is in the form of asphalt, a substance used for making roads. Sir Walter Raleigh visited the famous pitch lake of Trinidad in 1595; it is said to contain nine thousand million tons of asphalt. There are probably huge quantities of crude oil beneath the surface.

　　The king of the oilfield is the driller. He is a very skilled man. Sometimes he sends his drill more than a mile into the earth. During the process of drilling, gas and oil at great pressure may suddenly be met, and if this rushes out and catches fire the oil well may never be brought into operation at all. This danger is well known and steps are always taken to prevent it.

　　There is a lot of luck in drilling for oil. The drill may just miss the oil although it is near; on the other hand, it may strike oil at a fairly high level. When the drill goes down, it brings up soil. The samples of soil from various depths are examined for traces of oil. If they are disappointed at one place, the drillers go to another. Great sums of money have been spent, for example in the deserts of Egypt, in "prospecting" for oil. Sometimes little is found. When we buy a few gallons of petrol for our cars, we pay not only the cost of the petrol, but also part of the cost of the search that is always going on.

　　1. The purpose of lubrication is to reduce friction.

　　2. Mineral oil became very important only when the oil wells were found in Pennsylvania.

　　3. Vegetable oil was unknown in ancient times.

　　4. The passage gives a general description of 3 main types of oils.

　　5. The Middle East is one of the four main areas of the world where deposits of oil appear.

　　6. On the Island of Trinidad, drilling is not necessary to obtain oil.

　　7. Whales are the largest animals now living in the world.

　　8. Scientists think that oil was formed from______in the sea.

　　9. The cost of unsuccessful drilling is included in______of petrol.

　　10. The driller is unlucky when the drill goes very near oil without _^_____it.

　　I. Y 2. N 3. N 4. N 5. NG 6. Y 7. Y 8. living things 9. the selling price 10. striking

　　相關(guān)推薦：

　　沖刺必看：英語四級考試閱讀題之猜詞技巧

　　2011年英語四級考試閱讀理解專項練習(xí)題匯總

　　2011年下半年英語四級閱讀：畢業(yè)季我的記憶