【正文】 Mr. Rector and others argued that once amp。 says Kathy Lairn，a policy analyst at the Center on Budget and Policy Pricorities in Washington.A center analysis of US Census data nationwide found that between 1995 and 1996, a greater percentage of single, femalea2headed households were earning money on their own, but that average ine for these households actually went down.but for many, the fact that poor people are able to support themselves almost as well without government aid as they did with it is in itself a huge victory.amp。 and 2) How bad the consequences if the event think an asteroid big enough to destroy lots of life might strike Earth once eve ry 500，000 pretty rarebut if one did fall，it would be the end of the world.―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 we really want fleets of nuclear weapons sitting around on Earth?―The world has less to fear fromdoomsday(毀滅性的) rocks than from a great nuclear fleet set against them，‖ said a New York Times article. 21. What does the passage say about asteroids and meteoroids?A) They are heavenly bodies different in position.B) They are heavenly bodies similar in nature.C) There are more asteroids than meteoroids.D) Asteroids are more mysterious than meteoroids.22. What do scientists say about the collision of an asteroid with Earth?A) It is very unlikely but the danger exists.B) Such a collision might occur once every 25 years.C) Collisions of smaller asteroids with Earth occur more often than expected.D) It’s still too early to say whether such a collision might occur..23. What do people think of the suggestion of using nuclear weapons to alter the course of asteroids? 1 A) It sounds practical but it may not solve the problem.B) It may create more problems than it might solve.C) It is a waste of money because a collision of asteroids with Earth is veryunlikely.D) Further research should be done before it is proved applicable.24. We can conclude from the passage that .A) while pushing asteroids off course nuclear weapons would destroy the worldB) asteroids racing across the night sky are likely to hit Earth in the near futureC) the worry about asteroids can be left to future generations since it is unlikely to happen in our lifetimeD) workable solutions still have to be found to prevent a collision of asteroids with Earth.25. Which of the following best describes the author’s tone in this pass age?A) Optimistic. B) Critical. C) Objective. D) Arbitrary. Questions 26 to 30 are based on the following passage:Believe it or not，optical illusion (錯覺) can cut highway is a case in has reduced automobile crashes on some roads by nea rly 75 percent using a simple optical stripes，called chevrons (人字形)painted on the roads make drivers think that they are d riving faster than they really are，and thus drivers slow the American Association Foundation for Traffic Safety in Washington planning to rep eat Japan’s next year,the foundation will paint chevrons and other patterns of stripes on selected roads around the country to test how well the patterns reduce highway speed plays a major role role in as much as one fifth of all fatal traffic accidents,according to the foundation .To help reduce those accidents，the foundation will conduct its tests in areas where speed related hazards are the greatest curves，exit slopes，traffic c ircles，and studies suggest that straight，horizontal bars painted across roads can initially cut the average speed of drivers in ，t raffic often returns to full speed within months as drivers bee used to seeing the painted ，scientists say，not only give drivers the impress ion that they are driving faster than they really are but also make a lane sppea r to be result is a longer lasting reduction in highway speed and the number of traffic accidents. 26. The passage mainly discusses . 2 A) a new way of highway speed controlB) a new pattern for painting highwaysC) a new approach to training driversD) a new type of optical illusion27. On roads painted with chevrons drivers tend to feel that.A) they should avoid speed related hazardsB) they are driving in the wrong laneC) they should slow down their speedD) t