One reason researchers have long believed that Mars never enjoyed an extensive period of warm and wet climate is that much of th

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问题     One reason researchers have long believed that Mars never enjoyed an extensive period of warm and wet climate is that much of the surface not covered by wind-borne dust appear to be composed of unweathered material. If water flowed for an extended period, researchers reasoned, it should have altered and weathered the volcanic minerals, creating clays or other oxidized, hydrated phases (minerals that incorporate water molecules in their crystal structure).
    It turns out, though, that the scientists were not looking closely enough. New high-resolution mapping data and close-up surface studies have revealed clays and other hydrated minerals in many regions. The clay deposits are scattered all over, in ancient volcanic surfaces and heavily cratered highland regions, some of which have apparently been exposed by erosion only recently.
It can be inferred from the passage that the author would agree with which of the following statements regarding the reasoning discussed in the highlighted sentence?

选项 A、It provides the basis for an explanation of why water on Mars has been difficult to find until recently.
B、It correctly identifies a consequence of water flowing on the Martian surface.
C、It depends on a false assumption about how water and volcanic materials interact on Mars.

答案B

解析 标黑体句子的作用就是提供原理去解释为什么火星表面物质会成为辨别火星是否有水的证据,因此选项B正确。a consequence指的是水流经表面后产生黏土和水合物。在第二段,作者也利用了这个原理来说明火星其实是有水的,因此标黑体句子本身是准确的。A项文章没有解释为什么火星很难找到水。C项水和火星物质之间的作用就是水会侵蚀这些物质,这一假设是正确的。
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本试题收录于: GRE VERBAL题库GRE分类
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