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

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.
According to the passage, scientists are able to discover weathered material on the Martian surface because they have benefited from which of the following?
选项 A、A new method to analyze volcanic craters created on the Martian surface.
B、An improved ability to detect hydrated materials on the Martian surface
C、A more sophisticated understanding of the effect of wind-borne dust on the Martian surface
D、A decision to look for water primarily in heavily cratered highland regions.
E、A better understanding of how erosion might affect clay deposits.
答案B
解析 根据第二段，科学家之所以又开始认为火星有水，是受益于新的技术使他们找到了水存在的证据，即黏土和其他水合物，因此选项B正确。
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