听力题 Unless we spend money to and prevent asteroids, i.e. minor planets, one might (36) 1 into earth and destroy life as we know it, say some scientists. Asteroids are bigger (37) 2of the meteoroids that race across the night sky. Most orbit the sun far from earth and don''t (38) 3us. But there are also (39) 4whose orbits put them on a (40) 5course with earth. Buy $50 million worth of new (41) 6right now. Then spend $ 10 million a year for the next 25 years to locate most of the space rocks. By the time we (42) 7a fatal one, the scientists say, we''ll have a way to change its course. Some scientists favor pushing asteroids off course with nuclear (43) 8. But the cost wouldn''t be cheap. Is it worth it? Two things experts consider when judging any risk are: (44) 9Experts think an asteroid big enough to destroy lots of life might strike earth once every 500,000 years. (45) 10. "If we don''t take care of these big asteroids, they''ll take care of us," says one scientist. "It''s that simple." The cure, though, might be worse than the disease. (46) 11? "The world has less to fear from doomsday rocks than from a great nuclear fleet set against them," said a New York Times article.