The ocean bottom (a region nearly 2.5 times greater than the total land area of the Earth) is a vast frontier that even today is

admin2010-07-06  40

问题       The ocean bottom (a region nearly 2.5 times greater than the total land area of the Earth) is a vast frontier that even today is largely unexplored and uncharted. Until about a century ago, the deep-ocean floor was completely inaccessible, hidden beneath waters averaging over 36,000 meters deep. Totally without light and subjected to intense pressures hundreds of times greater than at the Earth’s surface, the deep-ocean bottom is a hostile environment to humans, in some ways as forbid- ding and remote as the void of outer space.
      Although researchers have taken samples of deep-ocean rocks and sediments for over a century, the first detailed global investigation of the ocean bottom did not actually start until 1968, with the beginning of the National Science Foundation’s Deep Sea Drilling Project (DSDP). Using techniques first developed for the offshore oil and gas industry, the DSDP’s drill ship, the Glomar Challenger, was able to maintain a steady position on the ocean’s surface and drill in very deep waters, extracting samples of sediments and rocks from the ocean floor.
      The Glomar Challenger completed 96 voyages in a 15-year research program that ended in November 1983, During this time, the vessel logged 600,000 kilometers and took almost 20,000 core samples of seabed sediments and rocks at 624 drilling sites around the world.  The Glomar Challenger’s core samples have allowed geologists to reconstruct what the planet looked like hundreds of millions of years ago and to calculate what it will probably look like millions of years in the future. Today, largely on the strength of evidence gathered during the Glomar Challenger’s voyages, nearly all earth scientists agree on the theories of plate tectonics and continental drift that explain many of the geological processes that shape the Earth.
     The cores of sediment drilled by the Glomar Challenger have also yielded information critical to understand the world’s past climates. Deep-ocean sediments provide a climatic record tracing back hundreds of millions of years, because they are largely isolated from the mechanical erosion and the intense chemical and biological activies that rapidly destroy much land-based evidence of past climates. This record has already provided insights into the patterns and causes of past climatic change information that may be used to predict future climates.
The Deep Sea Drilling Project was of great significance because it was______.

选项 A、the first attempt to use a special technique.
B、the first extensive exploration of the ocean bottom.
C、attracting many geologists from all over the world.
D、of great importance to funds of the gas and oil industry.

答案B

解析 本题是一个推断题,要求考生对一个推断的理由作出解释。解答这种类型的推断题要求考生能够理解这句话在整个段落中的作用,分析具体句子:“The first detailed global investigation of the ocean bottom did not actually start until 1968,with the beginning of the National Science Foundation’s Deep Sea Drilling Project (DSDP).Using techniques first developed for the offshore oil and gas industry,the DSDP’s drill ship,the Glomar Challenger,was able to maintain a steady potation on the ocean’s surface and drill in very deep waters,extracting samples of sediments and rock from the ocean floor.”注意这里前后两句话的关系。第二句话并没有对前面的论述作一个解释,而是对这个项目作一个一般性的说明。
转载请注明原文地址:https://kaotiyun.com/show/30Dd777K
0

最新回复(0)