問題詳情

II. Reading comprehension (每題 2 分，10 題，共 20 分)The Big Bang theory holds that the universe began with a big explosion some 15billion years ago. Radiation and cosmic materials have been flying outward ever since.These materials first condensed into gas; next, huge clouds of gas gathered aroundcores where the cosmic materials were denser than average. These cores, orgravitational centers, started pulling at the surrounding materials in a process calledgravitational condensation. This process resulted eventually in both of galaxies, starsand planets.The first evidence supporting the Big Bang came in 1964, when scientistsdetected the gamma ray background radiation which was thought to be a remnantfrom the original explosion. A second piece of evidence was recently located by theCosmic Background Explorer (COBE) satellite. In order for cosmic materials tocondense into galaxies, there must first be cores of higher-density materials to functionas centers of gravitational condensation. Did these cores really exist? COBE sent backpictures of huge cosmic clouds about 15 billion light years away, or 15 billion yearsago. That was just a little while—about 300,000 years—after the birth of the universe.The largest cloud observed by COBE was 10 billion light years across! After computeranalysis, a cosmic map was charted which showed spots of higher temperature—andthus of greater density. These were the cores that Big Bang scientists had been lookingfor.COBE provided evidence for another celestial controversy. Will the universe goon expanding forever, gradually cease to expand, or fall back on itself? The answerdepends on the density of matter in the universe. If the density is low, the gravitationalpull will be too slight to check the expansion, and the universe will go on flying aparttill the end of time. If the density is high enough, gravity will eventually pull cosmicmatter—galaxies, stars and clouds—back toward a grand collision and another BigBang. If it is exactly at critical density, the universe will slowly cease to expand andeventually reach a static state. The information sent back by COBE supports the lastalternative.
41. What is the author’s purpose in writing this passage?
(A)To question the validity of the Big Bang theory.
(B) To speculate on the ultimate end of our universe.
(C) To introduce various theories of the origin of the universe.
(D)To report on a satellite’s findings that support the Big Bang theory.7

參考答案

答案：A
難度：困難0.363636
統計：A(4),B(1),C(0),D(3),E(0)

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