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Directions:You are going to read a list of headings and a text about natural selection. Choose the most suitable heading from the list A—F for each numbered paragraph (41—45). The first and last paragraphs of the text are not numbered. There is one extra heading which you do not need to use. Mark your answers on ANSWER SHEET 1.[A] The impotence of creationism.[B] Natural selection acts by competition.[C] The role of natural selection in this colorful world[D] The delicate hierarchy of the natural system.[E] The agency of selection can account for more cases.[F] No leaps in natural evolution.As each species tends by its geometrical rate of reproduction to increase excessively in number; and as the modified descendants of each species will be enabled to increase by as much as they become more diversified in habits and structure, so as to be able to seize on many and widely different places in natural selection to preserve the most divergent offspring of any one species. Hence, during a long-continued course of modification, the slight differences characteristic of varieties of the same species, tend to be augmented into the greater differences characteristic of the species of the same genus.41. __________New and improved varieties will inevitably displace and destroy the older, less improved, and intermediate varieties; and thus species are rendered to a large extent defined and distinct objects. Dominant species belonging to the larger groups within each class tend to give birth to new and dominant forms; so that each large group tends to become still larger, and at the same time more divergent in character. But as all groups cannot thus go on increasing in size, for the world would not hold them, the more dominant groups beat the less dominant.42. __________This tendency in the large groups to go on increasing in size and diverging in character, together with the inevitability of much extinction, explains the arrangement of all the forms of life in groups subordinate to groups, all within a few great classes, which has prevailed throughout all time. This grand fact of the grouping of all organic beings under what is called the Natural System, is utterly unexplainable on the theory of creation.43. __________As natural selection acts solely by accumulating slight, successive, favorable variations, it can produce no great or sudden modifications; it can act only by short and slow steps. We can see why throughout nature the same general end is gained by an almost infinite diversity of means, for every peculiarity when once acquired in long inherited, and structures already modified in many different ways have to be adapted for the same general purpose. We can, in short, see why nature is extravagant in variety, though not generous in innovation. But why this should be a law of nature if each species has been independently created no man can explain.44. __________Many other facts are, as it seems to me, explicable on this theory. How strange it is that a bird, under the form of a woodpecker, should prey on insects on the ground and that upland geese which rarely or never swim, should possess webbed feet, and so in endless other cases. But on the view of each species constantly trying to increase in number, with natural selection always ready to adapt the slowly varying descendants of each to any unoccupied or ill-occupied place in nature, these facts cease to be strange, or might even have been anticipated.45. __________We can to a certain extent understand how it is that there is so much beauty throughout nature; for this may be largely attributed to the agency of selection. That beauty, according to our sense of it, is not universal, must be admitted by every one who will look at some hideous bats with a distorted resemblance to the human face. Sexual selection has given the most brilliant colors, elegant patterns, and other ornaments to the males. With birds it has often rendered the voice of the male musical to the female, as well as to our ears. Flowers and fruit have been rendered conspicuous by brilliant colors in contrast with the green foliage, in order that the flowers may be readily seen, visited and fertilized by insects.As natural selection acts by competition, it adapts and improves the inhabitants of each country only in relation to their co-inhabitants; so that we need feel no surprise at the species of any one country being beaten and supplanted by the naturalized productions from another land. The wonder indeed is, on the theory of natural selection, that more cases of the want of absolute perfection have not been detected. 42
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The problem to be taken up and the point at which the search for a solution will begin are customarily prescribed by the investigator (1) a subject participating in an (2) on thinking (or by the programmer for a computer). (3) , prevailing techniques of (4) in the psychology of thinking have invited (5) of the motivational aspects of thinking. The conditions that determine when the person will begin to think in (6) to some other activity, what he will think about, what direction his thinking will take, and when he will regard his search for a solution as successfully terminated (or abandon it as not worth pursuing further) (7) are beginning to attract investigation. (8) much thinking is aimed at (9) ends, special motivational problems are raised by "disinterested" thinking, in which the (10) of an answer to a question is a source of satisfaction in itself.For computer specialists, the detection of a mismatch between the formula that the program so far has (11) and some formula or set of requirements that (12) a solution is what impels continuation of the search and determines the direction it will (13) .Neo-behaviorists (like psychoanalysts) have made much of secondary (14) value and stimulus generalization; i. e. , the tendency of a stimulus pattern to become a source of satisfaction if it resembles or has (15) accompanied some form of biological gratification. The insufficiency of this kind of explanation becomes apparent, (16) , when the importance of novelty, surprise, complexity, incongruity, ambiguity, and (17) is considered. Inconsistency between beliefs, between items of incoming sensory information, or between one’s belief and an item of sensory information (18) can be a source of discomfort impelling a (19) for resolution through reorganization of belief (20) or through selective acquisition of new information. Read the following text. Choose the best word (s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1.11（）
It may turn out that the "digital divide"—one of the most fashionable political slogans of recent years—is largely fiction. As you will recall, the argument went well beyond the unsurprising notion that the rich would own more computers than the poor. The disturbing part of the theory was that society was dividing itself into groups of technology "haves" and "have-nots" and that this segregation would, in turn, worsen already large economic inequalities. It is this argument that is either untrue or wildly exaggerated.We should always have been suspicious. After all, computers have spread quickly because they have become cheaper to buy and easier to use. Falling prices and skill requirements suggest that the digital divide would spontaneously shrink—and so it has.Now, a new study further discredits the digital divide. The study, by economist David Card of the University of California, Berkeley, challenges the notion that computers have significantly worsened wage inequality. The logic of how this supposedly happens is straightforward: computers raise the demand for high-skilled workers, increasing their wages. Meanwhile, computerization—by automating many routine tasks—reduces the demand for low-skilled workers and, thereby, their wages. The gap between the two widens.Superficially, wage statistics support the theory. Consider the ratio between workers near the top of the wage distribution and those near the bottom. Computerization increased; so did the wage gap.But wait, point out Card and DiNardo. The trouble with blaming computers is that the worsening of inequality occurred primarily in the early 1980s. With computer use growing, the wage gap should have continued to expand, if it was being driven by a shifting demand for skills. Indeed, Card and DiNardo find much detailed evidence that contradicts the theory. They conclude that computerization does not explain "the rise in U.S. wage inequality in the last quarter of the 20th century."The popular perception of computers’ impact on wages is hugely overblown. Lots of other influences count for as much, or more. The worsening of wage inequality in the early 1980s, for example, almost certainly reflected the deep 1981—1982 recession and the fall of inflation. Companies found it harder to raise prices. To survive, they concluded that they had to hold down the wages of their least skilled, least mobile and youngest workers.The "digital divide" suggested a simple solution (computers) for a complex problem (poverty). With more computer access, the poor could escape their lot. But computers never were the source of anyone’s poverty and, as for escaping, what people do for themselves matters more than what technology can do for them. F.It is generally believed that the digital divide is something（）
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