問題詳情

IV. Reading Comprehension: 20%(請注意：在第1篇文章中被標示的( A ) , ( B ) , ( C ) , ( D ) 為第 41題題目設計的一部份。 ) (第 1 篇) One of the most basic concepts in plate tectonics, the study of the movements ofthe earth’s crust, is the idea of continental drift. As even small children often realize whenstudying an atlas or a globe, the continents as we know them now seem to be pieces of anenormous jigsaw puzzle. ( A ) This is because the continents were once, in fact, parts of a singlesupercontinent called Gondwanaland. For eons, however, they have been moving apart, and theoceans separating them have been growing wider. In order for the seas to expand, there must besome mechanism by which the ocean floor can itself spread out to fill the space vacated by thecontinents, a process which was finally discovered by scientists in the 1920’s.( B ) Using sonar, a device that reads the reflected echoes of sound waves, and a speciallydeveloped magnetometer to measure magnetic fields, scientists discovered that the rocks closestto the mid-ocean ridges were younger than rocks found at a distance. ( C ) Further, closerinspection revealed that, while the sea floor close to these ridges was relatively free from debris,marine sediment became thicker as the distance from the ridges increased. Still more advancedtesting uncovered the fact that there were unusually warm currents emanating from the area ofthe ridges. All of these pieces of evidence pointed to one inevitable conclusion: new rock wassomehow being born there as the seafloor spread out from these ridges.So just how is this rock created? Magma (molten lava from the earth’s mantle) flowing upthrough the relatively thin crust of the ocean floor meets the cooler ocean water and quicklycoalesces, forming the rock of the mid-ocean ridges. ( D ) Because, however, this new rock hasno place to go, it exerts pressure against the sides of the fissure through which it emerged,widening the crack and “spreading” the floor of the ocean. It is precisely this mechanism thatforces the continental plates apart, and is responsible, at least in part, for continental drift.
41. The following sentence--As is often the case, advances in technology led the way toscientific knowledge—can be integrated into the passage. Please choose one from the( A )( B )( C )( D ) marked in the passage, where the sentence can best fit in .

參考答案

答案：B
難度：適中0.6
統計：A(0),B(3),C(2),D(0),E(0)

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