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[问答] jj长阅读请大神指教 [复制链接]

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发表于 2019-5-31 18:57:02 |显示全部楼层
本帖最后由 huang4900 于 2019-5-31 21:30 编辑

mages gathered during the 1989 Magellan mission showed evidence of fault zones and volcanoes, but resolved the debate about Venusian plate tectonics by revealing the Venus has no global network of plates like those on Earth. The challenge then became the explanation of Magellan’s findings. At the core of the ensuing debate were Venus’s impact craters. Astronomers commonly use craters to estimate the age of the surface of an astronomical body by calculating from the known frequency with which comets and meteors travel through the Solar System how long it would take to produce the number of craters present: the more craters there are, the older the landscape probably is. It is not surprising to
find regions of widely varying age on the same planet on Mars, for example, volcanism and erosion have erased craters in some areas, leaving a surface that is young and clean compared with the rest of the planet. Venus’s craters appear to be distributed randomly, suggesting that the entire surface is roughly the same age. The surface appears to be about 500 million years old. Since the age of the Solar System is estimated to be around 4.5 billion years, some astronomers hypothesize that a cataclysmic event caused the previous craters to become covered.
Global resurfacing theories posit that between 300 and 500 million years ago almost all the surface of Venus was wiped clean by geologic processes including volcanism. Such activity then slowed dramatically, leaving subsequent craters largely untouched. Resurfacing may be a recurring process, periodically subjecting the planet to volcanism that covers the surface in lava. Venting of heat lithosphere, thickens as the lava hardens, preventing new magma from reaching the surface. Craters formed on this new, hard surface remain largely intact. Heat is trapped in the interior until rising temperatures overwhelm the lithosphere, beginning the process again.

4. The information in the passage suggests that scientists who espoused global-resurfacing theories would be most likely to agree with which of the following statements?
A. Venus has not undergone a cataclysmic resurfacing since one that occurred between 300 and 500 million years ago.
B. The craters on the surface of Venus are all about the same age.
C. Global resurfacing has occurred numerous times on Venus.
D. The lithosphere of Venus is thicker than that of the Earth.
E. Some regions of the surface of Venus are much older than other regions.

这道题答案是A
我的问题是C哪里不对呢? 文章那段话讲的是周期性的火山作用 应该是有好几次了吧?(除非说是 300 and 500million years 的这次resurface 是第一次...)

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FALL祈福章

发表于 2019-5-31 20:20:00 |显示全部楼层
只有这一段,也看不出A啊。我估计上下文应该说了现在craters are intact吧
C:作者没说发生了很多次,上一次就可能是第一次,所以不能确定,不充分的不选
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发表于 2019-5-31 21:30:12 |显示全部楼层
本帖最后由 huang4900 于 2019-5-31 21:32 编辑
以希 发表于 2019-5-31 20:20
只有这一段,也看不出A啊。我估计上下文应该说了现在craters are intact吧
C:作者没说发生了很多次,上一 ...


enen

前面是讲通过v的craters判断v的年龄是500m年
这个c选项是很容易上当的;说他不对吧又有点对 很讨厌的选项

全复制出来 太吓人了 还是这样吧

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FALL祈福章

发表于 2019-5-31 22:16:40 |显示全部楼层
这是哪里的长文?

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