《考研英語(yǔ)閱讀理解100篇 高分版》 Unit 21 - TEXT THREE

The dinosaurs fell victim to an asteroid smashing into the Earth, but people have no plans to allow such a calamity to befall them. For the past decade or so, astronomers have been watching the skies to identify dangerous flying objects. One lump of rock, called Apophis, the Greek name for an Egyptian god of destruction, alarmed astronomers when it was first spotted in 2004. They now think it is extremely unlikely to hit the planet. Even so, a private company has just unveiled plans to visit it, in case Apophis does decide to pop in on Earth sometime soon.
The reason for the trip is that the orbits of asteroids are difficult to predict. Apophis is expected to sweep close enough to the Earth in 2029 to pass below the altitude of communications satellites. Depending on its exact path, it could pass through what is known as a keyhole—a narrow range of orbits—that would deflect it and cause it to crash into the planet when it comes round again exactly seven years later.
Hence the bid to launch a probe by Astrium, a spacecraft subsidiary of EADS, a European aerospace and defence giant. It would study the way in which Apophis is drifting because of the effects of sunlight and that would enable astronomers to plot its course more accurately. The probe would also map the details of Apophis's surface and determine its thermal properties, which would help identify the composition of the asteroid. Such information could prove invaluable if it became necessary to nudge the projectile from its path.
The idea is to launch the mission, called Apex, in 2013 and for it to rendezvous with the asteroid in January 2014. The probe would spend three years stalking Apophis so that, if it did appear to be heading towards the keyhole, action could be taken to divert it well before 2029. Improbable though astronomers think this particular impact may be, it would be good to know more about nearby asteroids so that when one does threaten to strike, its route can be changed. Apophis is some 350 metres across, considerably larger than the object that is thought to have flattened 2,000 square kilometres of Siberian forest as it vaporised in the atmosphere above Tunguska in 1908.
Smashing such an object to smithereens, a technique championed by Hollywood films, would be silly because the Earth would be pelted with lots of smaller bits of debris that could prove just as destructive, particularly near a city. Better to knock it off course or tow it away using the gravitational attraction of a spacecraft sent to divert it. The success of this approach would depend not only on the path the asteroid is expected to take, but also on how the material that forms it is bound together.
Astrium's plans have been submitted to the Planetary Society, a group of space enthusiasts that has stumped up $50,000 in prize money to inspire interest in a mission to Apophis. Given that the actual cost for such a mission would be more like $50m, both the American space agency, NASA, and its European counterpart are taking a close interest. It is they, after all, who would be footing most of the bill.
1. Apophis would probably hit on the Earth when _____.
[A] it passes through a narrow range of orbits which are equivalent of a keyhole
[B] it is forced to deviate from its original course when passing through the keyhole
[C] it passes below the altitude of communications satellites because of Earth's gravitation
[D] it comes round the Earth seven years later
2. The word “stalking” (Line 2, Paragraph 4) most probably means _____.
[A] investigating
[B] tracking
[C] approaching
[D] foregoing
3. Which one of the following statements is TRUE of the case of the object in 1908?
[A] The object threatened but failed to destroy 2,000 square kilometers of Siberian forest.
[B] The object dissolved in the air because it was too small to hit upon the Earth.
[C] The object turned out to be Apophis which visited the Earth seven years ago.
[D] The route of the object was thought by scientists to be impossible to head towards the Earth.
4. The technique of smashing the object to smithereens would be silly because _____.
[A] it is only a fictitious technique that people created for Hollywood films
[B] the smithereens may result in fatal damage to human habitats
[C] lots of dangerous debris would fly around the Earth under the gravitational attraction
[D] the asteroid would change its orbit and pose threat to the Earth when the object is smashed
5. Astrium's plans would be sponsored by _____.
[A] the Planetary Society which is supported by NASA
[B] the American and European space agencies
[C] space enthusiasts who donate prize money
[D] a private company called Astrium