2014年5月托福考试复习题及答案(第六套)_第3页

　　In July of 1994, an astounding series of events took place. The world anxiously　watched as, every few hours, a hurtling chunk of comet plunged into the atmosphere of　Jupiter. All of the twenty-odd fragments, collectively called comet Shoemaker-Levy 9　Line after its discoverers, were once part of the same object, now dismembered and strung out　(5) along the same orbit. This cometary train, glistening like a string of pearls, had been first　glimpsed only a few months before its fateful impact with Jupiter, and rather quickly　scientists had predicted that the fragments were on a collision course with the giant　planet. The impact caused an explosion clearly visible from Earth, a bright flaming fire　that quickly expanded as each icy mass incinerated itself. When each fragment slammed　　(10) at 60 kilometers per second into the dense atmosphere, its immense kinetic energy was　　transformed into heat, producing a superheated fireball that was ejected back through the　tunnel the fragment had made a few seconds earlier. The residues form these explo-　　sions left huge black marks on the face of Jupiter, some of which have stretched out to　from dark ribbons.

　　(15) Although this impact event was of considerable scientific importance, it especially piqued　public curiosity and interest. Photographs of each collision made the evening television　newscast and were posted on the Internet. This was possibly the most open scientific　endeavor in history. The face of the largest planet in the solar system was changed before　our very eyes. And for the very first time, most of humanity came to fully appreciate the　(20) fact that we ourselves live on a similar target, a world subject to catstrophe by random　assaults from celestial bodies. That realization was a surprise to many, but it should not　have been. One of the great truths revealed by the last few decades of planetary explo-　ration is that collisions between bodies of all sizes are relatively commonplace, at least in　geologic terms, and were even more frequent in the early solar system.

　　3. The author compares the fragments of comet Shoemaker-Levy 9 to all of the following EXCEPT

　　(A) a dismembered body

　　(B) a train

　　(C) a pearl necklace

　　(D) a giant planet

　　答案：D