Unless we spend money to spot and
prevent asteroids (小行星) now, one might crash into Earth and destroy
life as we know it, say some scientists. Asteroids are bigger
versions of the meteoroids (流星) that race across the night sky. Most
orbit the sun far from Earth and don’t threaten us. But there are also thousands
whose orbits put them on a collision course with Earth. Buy $ 40
million worth of new telescopes right now. Then spend $10 million a year for the
next 25 years to locate most of the space rocks. By the time we spot a fatal
one, the scientists say, we’ll have a w A. They are heavenly bodies different in composition. B. They are heavenly bodies similar in nature. C. There are more asteroids than meteoroids. D. Asteroids are more mysterious than meteoroids.
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