《2017年GRE阅读综合整理考前练习题及答案.docx》由会员分享，可在线阅读，更多相关《2017年GRE阅读综合整理考前练习题及答案.docx（2页珍藏版）》请在三一文库上搜索。
1、2017年GRE阅读综合整理考前练习题及答案The finding that there were rock-melting temperatures on asteroids for sustained periods is puzzling: asteroids heat source is unknown, and unlike planet-sized bodies, such small bodies quickly dissipate heat. Rubin suggests that asteroidsheat could have derived from collisions
2、 between asteroids. Skeptics have argued that a single impact would raise an asteroid s overall temperature very little and that asteroids would cool too quickly between impacts to accumulate much heat. However, these objections assumed that asteroids are dense, solid bodies. A recent discoverythat
3、asteroidsarehighly porous makes Rubin s hypothesis more plausible. When solid bodies collide, much debris is ejected, dissipating energy. Impacts on porous bodies generate less debris, so more energy goes into producing heat. Heat could be retainedas debris fall back into impact craters, creating an
4、 insulating blanket.1. The passage suggests that one factor that has made it difficult to account for the temperatures once reached by asteroids isA. a miscalculation of the frequency of asteroid collisionsB. a misconception about asteroids densityC. a mistaken assumption about what the heat source
5、of the asteroids wasD. an underestimation of the rate at which small bodies lose heatE. an erroneous view of how asteroids were formedConsider each of the choices separately and select all that apply.2. It can be inferred from the passage thatRubindisagrees with skeptics mentioned in the passage about which of the following?A. Whether porous bodies generate less debris when struck than do solid bodiesB. The temperaturesasteroids would have to reach fortheir rocks to have meltedC. The likely effect of impacts on asteroids temperatures答案： 2