TOEFL全新真试题

2021-10-29 10:46:12 27

TOEFL全新真试题

　　READING COMPREHENSION

　　Questions 1-9

　　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 3,600 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 forbidding 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, theGlomar Challenger, was able to maintain a

　　steady position on the ocean s surface and drill in very deep waters, extracting samples

　　of sediments and rock 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 hundred 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