GWD17-Q35

purpleelf

GWD17-Q35 to Q37:

(This passage was excerpted from material published in 1996.)

When a large body strikes a planet or moon, material is ejected, thereby creating a hole in the planet and a local deficit of mass.This deficit shows up as a gravity anomaly:the removal of the material that has been ejected to make the hole results in an area of slightly lower gravity than surrounding areas.One would therefore expect that all of the large multi-ring impact basins on the surface of Earth’s Moon would show such negative gravity anomalies, since they are, essentially, large holes in the lunar surface.Yet data collected in 1994 by the Clementine spacecraft show that many of these lunar basins have no anomalously low gravity and some even have anomalously high gravity.Scientists speculate that early in lunar history, when large impactors struck the Moon’s surface, causing millions of cubic kilometers of crustal debris to be ejected, denser material from the Moon’s mantle rose up beneath the impactors almost immediately, compensating for the ejected material and thus leaving no low gravity anomaly in the resulting basin.Later, however, as the Moon grew cooler and less elastic, rebound from large impactors would have been only partial and incomplete.Thus today such gravitational compensation probably would not occur:the outer layer of the Moon is too cold and stiff.

Q35:

According to the passage, the gravitational compensation referred to in line 33 is caused bywhich of the following?

A.A deficit of mass resulting from the creation of a hole in the lunar surface
B.The presence of material from the impactor in the debris created by its impact
C.The gradual cooling and stiffening of the Moon’s outer layer
D.The ejection of massive amounts of debris from the Moon’s crust
E.The rapid upwelling of material from the lunar mantle

答案是E，cuased by不是由。。。导致的嘛？？ 这里答案我觉得就是把 gravitational compensation 的过程说一遍啊，为什么选E？？？

lovedoublej

lz可能对题目的理解有点偏差，题目就是问这个结果是怎么发生的，本

来月球被砸了一个坑就少了质量，所以按理说这一块的引力是变小了，而事

实却是有些地方的引力反而更高了，题目就是问你这个gravitational

compensation的结果是被什么引起的，那么答案就是E啊
（lz可能是这么理解的：gravitational compensation是一个过程，问这个

过程的原因E就讲不通啊，所以换个角度思考问题，题目就是问这个结果是

怎么形成的，因为英语和中文意思的差异，有些时候很难免我们会对问题的

理解出现偏差，当Lz发现某个思路走不通的时候就不要硬想，换个角度思考

会好些，排除法，其他四个选项都明显错误）

sevenmileser

定位：when large impactors struck the Moon’s surface, causing millions of cubic kilometers of crustal debris to be ejected, denser material from the Moon’s mantle rose up beneath the impactors almost immediately, compensating for the ejected
material and thus leaving no low gravity anomaly in the resulting basin.
答案E  upwelling对应rose up。注意ETS习惯用分词compensating表示因果关系，对应题目中的caused by（很多语法和阅读题都是这个考法。。

purpleelf

many thanks