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Passage 1The future of space exploration depends on many things. It depends on how technology evolves, how political forces shape competition and partnerships between nations, and how important the public feels space exploration is. The near future will see the continuation of human space flight in Earth’s orbit and unpiloted space flight within the solar system. Piloted space flight to other planets, or even back to the moon, still seems far away. Any flight to other solar systems is even more distant, but a huge advance in space technology could drive space exploration into realms currently explored only by science fiction.The 1968 film 2001: A Space Odyssey depicted commercial shuttles flying to and from a giant wheel-shaped space station in orbit around Earth, bases on the moon, and a piloted mission to Jupiter. The real space activities of 2001 will not match this cinematic vision, but the 21st century will see a continuation of efforts to transform humanity into a spacefaring species.Perhaps the most difficult problem space planners face is how to finance a vigorous program of piloted space exploration, in Earth’s orbit and beyond. In 1998 no single government or international enterprise had plans to send people back to the moon, much less to Mars. Such missions are unlikely to happen until the perceived value exceeds their cost.One belief shared by a number of space exploration experts is that future lunar and Martian expeditions should be aimed at creating permanent settlements. The residents of such outposts would have to "live off the land," obtaining such necessities as oxygen and water from the harsh environment. On the moon, pioneers could obtain oxygen by heating lunar soil. In 1998 the Lunar Prospector discovered evidence of significant deposits of ice, a valuable resource for settlers, mixed with soil at the lunar poles. On Mars, oxygen could be extracted from the atmosphere and water could come from buried deposits of ice.The future of piloted lunar and planetary exploration remains largely unknown. Most space exploration scientists believe that people will be on the moon and Mars by the middle of the 21st century, but how they get there, and the nature of their visits, is a subject of continuing debate. Clearly, key advances will need to be made in lowering the cost of getting people off Earth, the first step in any human voyage to other worlds. It is predicted that people who will live on other planets would have to（）
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A型题 吗啡作用于延髓孤束核阿片受体引起（）
Passage OneQuestions 61 to 65 are based on the following passage:Why don’t birds get lost on their long migratory (迁徙的) flight Scientists have puzzled over this question for many years. Now they are beginning to fill in the blanks.Not long ago, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly mainly by night Tests with artificial (人造的) stars have proved conclusively that certain night-flying birds are able to follow stars in their long-distance flights.One such bird – a warbler – had spent its lifetime in a cage and had never flown under a natural sky. Yet it showed an inborn ability to use stars for guidance. The bird’s cage was laced under an artificial star-filled sky at migration time. The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the position of the artificial stars caused a change in the direction of his flight.Scientists think that warblers, when flying in daylight, use the sun for guidance. But stars are apparently their main means of directed flight in the night. What do they do when stars are hidden by clouds Apparently, they find their way by such landmarks as mountain ranges, coast lines and river courses. But when it is too dark to see these, the warblers circle helplessly, unable to find their way. What do we know about warblers as a whole
Some consumer researchers distinguish (1) "rational" motives and "emotional" (or "non-rational") motives. They use the term "rationality" (2) the traditional economic sense that assumes (3) consumers behave rationally when they carefully consider all alternatives (4) choose those that give them the greatest utility (i.e., satisfaction). (5) a marketing context, the term "rationality" implies that the consumer selects goods based (6) totally objective criteria, such (7) size, weight, price, and so on. "Emotional" motives imply the selection of goods (8) to personal or subjective criteria—the desire (9) individuality, pride, fear, affection or status. The assumption underlying this distinction is (10) subjective or emotional criteria do not maximize utility or satisfaction. (11) , it is reasonable to assume that consumers always attempt to select alternatives that, (12) their view, serve to maximize satisfaction. Obviously, the assessment of satisfaction is a very personal process, based (13) the individual’s own needs as (14) as on past behavioral, social, and learning experiences. What may appear (15) irrational to an outside observer may be perfectly rational (16) the context of the consumer’s own psychological field. For example, a product purchased to enhance one’s self-image (such as a fragrance) is a perfectly rational form of consumer behavior. (17) behavior did not appear rational to the person who undertakes it (18) the time that it is undertaken, obviously he or she would not do it. (19) the distinction between rational and emotional motives does not appear to be warranted. Some researchers go so far (20) to suggest that emphasis (21) "needs" obscures the rational, or conscious, nature of most consumer motivation. They claim that consumers act consciously (22) maximize their gains and minimize their losses; that they act not (23) subconscious drives but from rational preferences, (24) what they perceive to be (25) their own best interests. 22（）
Passage 3Du Bois was a sociological and educational pioneer who challenged the established system of education that tended to restrict rather than to advance the progress of black Americans. He challenged what is called the "Tuskegee machine" of Booker T. Washington, the leading educational spokesperson of the blacks in the U. S..A sociologist and historian, Du Bois called for a more determined and activist leadership than Washington provided.Unlike Washington, whose roots were is southern black agriculture, Du Bois’s career spanned both sides of the Mason-Dixon Line. He was a native of Massachusetts, received his undergraduate education from Fisk University in Nashville, did his graduate study at Harvard University, and directed the Atlanta University Studies of Black American Life in the South. Du Bols approached the problem of racial relations in the United States from two dimensions: as a scholarly researcher and as an activist for civil rights. Among his works was the famous empirical sociological study, The Philadelphia Negro: A Social Study, in which he examined that city’s black population and made recommendations for the school system. Du Bols’s Philadelphia study was the pioneer work on urban blacks in America.Du Bois had a long and active career as a leader in the civil rights movement. He helped to organize the Niagara Movement in 1905, which led to the National Association for the Advancement of Colored People (NAACP), established in 1909. From 1910 until 1934, Du Bois edited The Crisis, the major journal of the NAACP. In terms of its educational policy, the NAACP position was that all American children and youth should have genuine equality of educational opportunity. This policy, which Du Bois helped to formulate, stressed the following themes: (1) public s chooling should be free and compulsory for all American children; (2) secondary schooling should be provided for all youth; (3) higher education should not be monopolized by any special class or race.As a leader in education, Du Bois challenged not only the tradition of racial segregation in the schools but also the accommodationist ideology of Booker T. Washington. The major difference between the two men was that Washington sought change that was evolutionary in nature and did not upset the social order, whereas Du Bois demanded immediate change. Du Bois believed in educated leadership for blacks, and he developed a concept referred to as the "talented tenth," according to which 10 percent of the black population would receive a traditional college education in preparation for leadership. Which of the following statements is true according to the text（）
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