1995年8月托福考试阅读理解全真试题（上）(doc9).doc

Question 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 3,6000 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, 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 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 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 understanding the
world s past climates. Deep – ocean sediments provide a
climatic record stretching back hundreds of millions of years,
because they are largely isolated from the mechanical erosion and
the intense chemical and biological activITy 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.

1. The author refers to the ocean bottom as a "frontIEr" in line 2 because IT

(A) is not a popular area for scientific research
(B) contains a wide varIEty of life forms
(C) attracts courageous explorers
(D) is an unknown terrITory

2. The word "inaccessible" in line 4 is closest in meaning to

(A) unrecognizable
(B) unreachable
(C) unusable
(D) unsafe