阅读理解Economics can render service in the area of exchange, but its tools find less purpose when applied to paradigms dominated by alternative models of transactions and social relationships. In small groups gift-giving is substituted Line for the role of exchange, which entails obligation: people receiving gifts are expected to reciprocate in the future and this reciprocity binds small groups together, whereas exchange rarely does so. Two people exchange only when both benefit, neither incurring a social obligation as a result, and where social obligations exist, exchange may not work well. Exchange nevertheless allows for extremely complex interactions among strangers: when employing a product, a consumer benefits from the efforts of hundreds of anonymous people who have contributed to that commodity. Such analysis also has its limits in the case of an area such as government, for economics seeks regularities in social life, which are more likely to occur when no one individual has an appreciable effect on the group.

阅读理解One reason why a sheep, a less well-understood experimental subject than the laboratory mouse, should have proved easier to clone may stem from differences in the initial stages of the two species'' embryonic development. After reaching maturity in the ovary of the mother, the unfertilized eggs of all mammals accumulate a supply of proteins, and the means of producing fresh protein. In this way, the mammalian egg brings with it a larder for the embryo to make use of until its own genes activate and supply this requirement themselves. The sheep embryo disposes of its store properly and need not depend on its own genes until the sixteen-cell stage, four cell divisions successive to fertilization, while in contrast, the mouse embryo commences this process more precociously, becoming reliant on the activity of its own genes after just the first division when the fertilized egg becomes two cells. Therefore, a foreign nucleus introduced into a sheep egg exploits a respite in its host''s biological development, allowing it to adapt to its new role before assuming genetic control. 　　Concomitantly, a nucleus introduced into a mouse egg must acclimatize quickly for its genes to be able to direct embryonic development within a single cell division, so perhaps there is insufficient time for the extensive re-programming of compulsory gene activity. The human embryo is thought to rely on its own genes after three cellular divisions, which might or might not provide time enough for a foreign nucleus to acclimate. However, were scientists to comprehend the nature of the indispensable re-programming then there is every likelihood that both mice and humans could be cloned. 　　Despite the long-standing availability of this technology, there has until recently been little interest in it. Some people suffering from infertility as a result of rare hereditary diseases could produce offspring, but cloned individuals may be at risk given scientists'' limited knowledge of the long term effects of allowing an "old" adult cell nucleus to commence life again in an egg. The nucleus of a skin cell could have accumulated a multitude of genetic mistakes of no consequence to its role in the skin, but the same cell could prove deleterious in other tissues, or immensely increase the probability of the affliction with cancer. The threat to general human health posed by cloning, as opposed to the individual, is difficult to determine, but the risks are almost certainly lower than those encountered in the effective inbreeding of consanguine marriages, and thus there are no scientific grounds per se for banning cloning. Like other practices inconsequential to the physical well being of humanity, but generally deemed undesirable on moral or social grounds, the prohibition of human cloning will ultimately rest with only a simple pragmatic decision.

阅读理解Previously, the sack-like rabbit appendix was thought to serve primarily as a reservoir for the bacteria involved in hindgut fermentation, a explanation that failed to account for the absence of an appendix in other animals with similar digestive systems or for its presence in humans. Microscopic research revealed that the appendix contains a significant amount of lymphoid tissue, similar aggregates of which tissue occur in other areas of the gastrointestinal tract. These are involved, possibly, in the body''s ability to recognize foreign antigens in ingested material, but the evidence is inconclusive, to the extent that scientists have long discounted the human appendix as a "vestigial" organ. However, a growing body of evidence suggests that the appendix, far from being a "vestigial organ", hag a significant function as a part of the body'' s immune system. The appendix achieves its greatest development shortly after birth, when immune response is first developing, then regresses with age, when the immune response mediated by the appendix may relate to such inflammatory conditions as ulcerative colitis, which in adults necessitates the organ'' s surgical removal.

阅读理解McClary''s position, concerning the process by which music is gendered as masculine or feminine, is that socially-grounded codes are "composed into" the music, that they are immanent to the text, there to be discovered. McClary has traced narratives of power and sexual differences in sonata forms by mapping the gendered terms in which theorists have described them onto pieces which variously appear to enact or resist such constructions. 　　Rieger has likewise traced the inchoate differentiation of musical affects by gendered characters in late-eighteenth-century opera, and charted their much heightened divergence in contemporary film music. Both of these approaches　share a common assumption of a degree of awareness of such gendered codes at the point of composition, an awareness which, if not fully reflective, at least shows a composer''s "practical consciousness" of how musical expression works　within his or her culture. This conception permits music to participate fully in cultural processes, thereby allowing us to bring cultural contexts to bear in our　explanatory models of musical styles and forms, but its critics rightly argue that it carries an extreme risk: it is all too easy for this approach to re-inscribe the values it would aim to critique. We may accuse McClary of adopting the very　stereotypes she deplores, and similarly we may regard her identification of musical difference with cultural difference to be an overinterpretation, though　unless we limit our focus to some extreme of the avant-garde, we must concede that some kind of contrast between masculinity and femininity will always exist in any music. 　　It is perhaps best to argue the possibility that such gender metaphors are merely functions of our interpretational frameworks, imposed on music from the outside. Treitler describes the way in which scholars from the eighteenth to the twentieth centuries have differentiated between Old Roman and Gregorian chant repertories in gendered terms, and argues that these metaphors relate entirely to a project of Western cultural supremacy, and not to any immanent musical characteristics of the actual chants. We may make the same point about all repertories: gender is encoded not in the music, but in the critical language we use, much like Pigmalion''s chisel, to bring the music to life. While this position is weaker than McClary''s in an explanatory capacity―it cannot use social values to account for why a piece was written the way it was rather than any other, aesthetically speaking--its value is ultimately greater in that it allows us to develop fresh listening strategies which invest familiar and well-loved music with new and arguably more positive values. Hence, it is more attractive for the development of a politically responsible critical strategy, though even in this respect, the position is not without shortcomings, most of which become apparent when we examine the relationship between musical　material and cultural meaning.

阅读理解Crosby''s recent study of American historical demography is blithely based on the reconstitution of the records of single parishes, a method that often excludes migrants. Moreover, it is troublesome for historians to obtain information on the birthdates of people who relocated to the parish, and equally difficult to follow those who had migrated to new places of residence. Thus, the exclusion of migrants also followed from the way spatial units were once conceived by the parishioners themselves, a stable and unchanging pre-modern countryside of interchangeable towns unlike "modern" flows to cities. 　　As a result, migration was improperly assumed to be irrelevant because the small units in the countryside were interchangeable and migrants into a parish could thus stand as a proxy for those who had left. In any case, it was thought that migration in the countryside was repetitive and occurred only in response to life course events, such as finding a spouse, and thus, like the parishioners themselves, Crosby complacently equates the demographics of migrants to those of more sedimentary populations.

阅读理解Most words are "lexical words", i.e. nouns signifying "things", the majority of which are abstract concepts rather than physical objects in the world; only "proper nouns" have specific and unique referents in the everyday world. The communicative function of a fully-functioning language requires the scope of reference beyond the particularity of the individual instance. While each leaf, cloud or smile is different from all others, effective communication requires general categories or "universals". Anyone who has attempetd to communicate with people who do not share their language will be familiar with the limitations of simply pointing to things, given that the vast majority of lexical words in a language exist on a high level of abstraction and refer to classes of things such as "buildings" or to concepts like "construction". 　　We lose any one-to-one correspondence of word and thing the moment we group instances into classes. Other than lexical words, language consists of "function words" or grammatical words, such as "only" and "under" which do not refer to objects in the world at all, and many more kinds of signs other that simple nouns. The notion of words as labels for concepts assumes that ideas exist independently of words and that ideas are established in advance before the introduction of linguistic structure. Clearly, language is not limited to naming things existing in the physical world, but includes non-existent objects and ideas well.　The nomenclaturist stance, in viewing words as labels forpre-existing ideas and objects, attempts unsuccessfully to reduce language to the purely referential function of naming things. Things do not exist independently of the sign systems which we use; "reality" is created by the media which seem simply to represent it. Language does not simply name pre-existing categories; categories do not exist in "the world" . e. g. "where are the boundaries of a cloud; when does a smile begin". Such an emphasis on reality as invariably perceptually seamless may be an exaggeration; our referential categories do seem to bear some relationship to certain features which seem to be inherently salient. Within a language, many words may refer to "the same thing" but reflect different evaluations of it. For example, ''one person''s ''hovel'' is another person''s '' home''" 　　Meanwhile, the signified of a word is subject to historical change. In this sense, "reality" or "the world" is created by the language we use: this argument insists on the primacy of the signifier. Even if we do not adopt the radical stance that "the real world" is a product of our sign systems, we must still acknowledge the lack of signifiers for many things in the empirical world and that there is no parallel correlation between most words and objects in the known world at all. Thus, all words are "abstractions", and there is no direct correspondence between words and "things" in the world.

阅读理解Scientists studying the effect of large volcanic eruptions on global climate have long focused on the major quantities of carbon dioxide (C02), a gas known to contribute to the greenhouse effect, produced by these eruptions. It is well observed that such greenhouse gases trap heat radiated from the surface of the earth, thereby forming a type of insulation around the planet. The greenhouse effect is essential for ecological equipoise because it maintains the temperature of the planet within habitable parameters, but there is growing concern that man-made production of gases such as CO[,2] from the burning of fossil fuels may be threatening the system''s tolerance, and have resulted in excessive warming on a global scale. While volcanic eruptions indubitably metabolize and accumulate C0[,2] in the atmosphere, it has been recently discovered that their impact is virtually trivial compared to the quantity produced by human activities, especially heavy industry. In reality, the more substantive climatic effect from volcanoes results from the production of atmospheric haze, whereby large eruption columns inject ash particles and sulfur-rich gases into the troposphere and stratosphere, clouds that circumscribe the globe within weeks of the volcanic activity. Ash and aerosol clouds from large volcanic eruptions disseminate quickly through the atmosphere, and the small ash particles decrease the amount of sunlight reaching the surface of the earth and lower average global temperatures, while the sulfurous gases combine with water in the atmosphere to form acidic aerosols that also absorb incoming solar radiation and scatter it back out into space. 　　There is evidence that volcanoes'' stratospheric ash clouds has a lesser effect on global temperatures than aerosol clouds, given that the major Mt. St. Helens eruption had lowered global temperatures by about 0.1 degree C, while two years later the much smaller eruption of El Chico had, by contrast, three to five times the global cooling effect worldwide. Despite its smaller ash cloud, El Chico emitted more than 40 times the volume of sulfur-rich gases produced by Mt. St. Helens, revealing that the formation of atmospheric sulfur aerosols has a more substantial effect on global temperatures than simply the volume of ash produced during an eruption. Sulfate aerosols appear to necessitate several years to settle out of the atmosphere, one of the reasons their effects are so widespread and enduring. This corroborates the opinion of those scientists who argue that without the cooling effect of major volcanic eruptions such as El Chico, global warming effects caused by human activities would be far more substantial. It should be noted that major volcanic eruptions have additional climatic effects beyond global temperature decreases and acid rain, for ash and aerosol particles suspended in the atmosphere scatter light of red wavelengths, often resulting in brilliantly colored sunsets and sunrises around the world.

阅读理解Since her own era, Christina Rossetti''s devout Christianity has often been seen as a characteristic setting her apart from the other avowedly non-Christian members of the Pre-Raphaelite circle. In designating their movement a form of"aesthetic mysticism", one established critic, Alice Law described the place Pre-Raphaelitism holds in the development of Victorian artistic culture as a movement away from a predominantly religious and moralizing function toward a culture of aestheticism―precisely what Rossetti''s work has long been thought to reject. The Pre-Raphaelites'' attention to picturesque detail, the medievalist atmosphere and settings, the pervasive melancholy of their works, and their awareness of their art''s primarily Christian literary and pictorial origins―all these have been traditionally downplayed in their similarity to the characteristics of Christina Rossetti''s poetry. 　　This belief persists, despite the distinctly religious "atmosphere" of much of the work produced by both generations of Pre-Raphaelites: its employment of biblical images and typology; of religious figural language; and, more especially and pervasively, of medievalist backgrounds and settings that were seen by their early audiences to have clearly devotional, if not dangerously "Romanist", associations. When discussing Pre-Raphaelitism as an historical movement, we must remember that the first brotherhood was inspired largely by a sacramental aesthetic that tended to alienate Victorian society, which generally abhorred the notion of sacrifice. It is true that Rossetti''s traditional solution to the Romantic and Victorian literary problem of alienation from nature and the more characteristically Victorian problem of despair at life''s meaninglessness, was fundamentally Christian. But with few exceptions, Rossetti relied on the colloquial and angst-ridden language of both generations of Pre-Raphaelites. Even Swinburne, the Pre-Raphaelite whose anti-orthodoxy and iconoclasm seem to conflict most profoundly with Rossetti''s values, enthusiastically hailed her. 　　That most Victorians themselves perceived Christina Rossetti as unequivocally Pre-Raphaelite in her poetic affinities is clear, for throughout her poetry and much of her prose Christina Rossetti demonstrated true and deep affinities with Pre-Raphaelite aesthetic values, in both innovative and traditional ways. We must not forget her "pictorial" modes of representation, the medieval atmosphere and settings that appear repeatedly in her poems, her appreciation of the world''s physical beauty and its expression in lush images, the intensity of her poems, which seems inseparable from their "sincerity", and not least her preoccupation with love. To a greater extent than figures more peripheral to the Pre-Raphaelite circle, Christina Rossetti produced works that appear to be dominated by the same aesthetic consciousness and literary values that make Pre-Raphaelitism the central movement which unintentionally spawned the aestheticism of the 1880s and 1890s. Pre-Raphaelitism, in fact, influenced aesthetic thought in a way that made the movement central to the transition from the sentimental moral idealism of the Victorian mainstream to the variously nihilistic, skeptical, and ironic value systems that dominate modern poetry.

单选题Analogies

单选题 k ak pk 1 100 0.10 2 200 0.25 3 300 0.20 4 400 0.25 5 500 0.20 If in an experiment the probabilities of obtaining the values a1，a2，a3，a4， and a5are p1，P2，P3，P4 and P5，respectively，then the expected value is defined as a1p1+a2p2+a3p3+a4p4+a5p5．For the values and their corresponding probabilities in the table above，what is the expected value? A. 350 B. 320 C. 300 D. 270 E. 250

单选题If a particular vaccine is produced only by one company at a single facility, there is a possibility that the supply of vaccine could grow ------- if the company decides to cease production.

单选题In a happy, somewhat boisterous celebration of the European discovery of America, the major phase of the Columbus Cinquecentennial got off to ______start on Friday.(A) a slow(B) a rousing(C) a reluctant(D) an indifferent(E) a quiet

单选题IMMEDIATE:

单选题ADHERENT:(A) fugitive(B) dissembler(C) opponent(D) educator(E) witness

单选题The authority of voice in Frazer's writing strikes many readers today as ______ colonialism; his prose seems as invulnerable and expansive as something on which the sun was presumed never to set.(A) consonant with(B) independent of(C) ambivalent toward(D) cognizant of(E) detrimental to

单选题Childhood memoirs often gain their poignancy through a sense of displacement: each lesson in experience is accompanied by a loss of-------.

单选题xpercentof24is12

单选题MOLLIFY:(A) instigate(B) instill(C) ire(D) subside(E) combat

单选题The author regards the idea that gendering stems from a composer's "practical consciousness" of how musical expression works with(A) serious caution(B) strong indignation(C) marked indifference(D) moderate amusement(E) sharp derision

单选题 Body language involves a combination of multiple facial (i) ______ and various physical positions to convey its unique (ii) ______ message. 　Blank(i) 　　　　　Blank(ii) terminology oral expressions strident appearance nonverbal