【文章內(nèi)容簡介】 ag others as antiscience. \[D\] Tagging environmentalists as antiscience is justifiable. 22. The author39。s attitude toward the issue of science vs. antiscience is. \[A\] impartial\[B\] subjective \[C\] biased\[D\] puzzling Passage 4 Emerging from the 1980 census is the picture of a nation developing more and more regional petition, as population growth in the Northeast and Midwest reaches a near standstill. This developmentand its strong implication for US politics and economy in years aheadhas enthroned the South as America39。s most densely populated region for the first time in the history of the nation39。s head counting. Altogether, the US population rose in the 1970s by million peoplenumerically the third largest growth ever recorded in a single decade. Even so, that gain adds up to only percent, lowest in American annual records except for the Depression years. Americans have been migrating south and west in larger numbers since World War II, and the pattern still prevails. Three sunbelt statesFlorida, Texas and Californiatogether had nearly 10 million more people in 1980 than a decade earlier. Among large cities, San Diego moved from 14th to 8th and San Antonio from 15th to 10thwith Cleveland and Washington, ., dropping out of the top 10. Not all that shift can be attributed to the movement out of the snow belt, census officials say. Nonstop waves of immigrants played a role, tooand so did bigger crops of babies as yesterday39。s baby boom generation reached its childbearing years. Moreover, demographers see the continuing shift south and west joined by a related but newer phenomenon: More and more, Americans apparently are looking not just for places with more jobs but with fewer people, too. Some instances ■ Regionally, the Rocky Mountain states reported the most rapid growth percent since 1970 in a vast area with only 5 percent of the US population. ■ Among states, Nevada and Arizona grew fastest of all: and percent respectively. Except for Florida and Texas, the top 10 in rate of growth is posed of Western states with million peopleabout 9 per square mile. The flight from overcrowdedness affects the migration from snow belt to more bearable climates. Nowhere do 1980 census statistics dramatize more the American search for spacious living than in the Far West. There, California added million to its population in the 1970s, more than any other state. In that decade, however, large numbers also migrated from California, mostly to other parts of the West. Often they choseand still are choosingsomewhat colder climates such as Oregon, Idaho and Alaska in order to escape smog, crime and other plagues of urbanization in the Golden State. As a result, California39。s growth rate dropped during the 1970s, to 18. 5 percentlittle more than two thirds the 1960s39。 growth figure and considerably below that of other Western states. 23. Discerned from the perplexing picture of population growth the 1980 census provided, America in 1970s. \[A\] enjoyed the lowest growth of population in history \[B\] witnessed a southwestern shift of population \[C\] underwent an unparalleled period of population growth \[D\] brought to a standstill its pattern of migration since World War II 24. The census distinguished itself from previous studies on population movement in that . \[A\] it stresses the climatic influence on population distribution \[B\] it highlights the contribution of continuous waves of immigrants \[C\] it reveals the Americans39。 new pursuit of spacious living \[D\] it elaborates the delayed effects of yesterday39。s baby boom 25. We can see from the available statistics that. \[A\] California was once the most thinly populated area in the whole US \[B\] the top 10 states in growth rate of population were all located in the West \[C\] cities with better climates benefited unanimously from migration \[D\] Arizona ranked second of all states in its growth rate of population 26. The word demographers (Line 1, Paragraph 7) most probably means. \[A\] people in favor of the trend of democracy \[B\] advocates of migration between states \[C\] scientists engaged in the study of population \[D\] conservatives clinging to old patterns of life Passage 5 Scattered around the globe are more than 100 small regions of isolated volcanic activity known to geologists as hot spots. Unlike most of the world39。s volcanoes, they are not always found at the boundaries of the great drifting plates that make up the earth39。s surface。 on the contrary, many of them lie deep in the interior of a plate. Most of the hot spots move only slowly, and in some cases the movement of the plates past them has left trails of dead volcanoes. The hot spots and their volcanic trails are milestones that mark the passage of the plates. That the plates are moving is now beyond dispute. Africa and South America, for example, are moving away from each other as new material is injected into the sea floor between them. The plementary coastlines and certain geological features that seem to span the ocean are reminders of where the two continents were once joined. The relative motion of the plates carrying these continents has been constructed in detail, but the motion of one plate with respect to another cannot readily be translated into motion with respect to the earth39。s interior. It is not possible to determine whether both continents are moving in opposite directions or whether one continent is stationary and the other is drifting away from it. Hot spots, anchored in the deeper layers of the earth, provide the measuring instruments needed to resolve the question. From an analysis of the hotspot population it appears that the African plate is stationary and that it has not moved during the past 30 million years. The significance of hot spots is not confined to