单选题By almost every measure, Paul Pfingst is an unsentimental prosecutor. Last week the San Diego County district attorney said he fully intends to try suspect Charles Andrew Williams, 15, as an adult for the Santana High School shootings. Even before the tragedy, Pfingst had stood behind the controversial California law that mandates treating murder suspects as young as 14 as adults. So nobody would have wagered that Pfingst would also be the first D. A. in the U. S. to launch his very own Innocence Project. Yet last June, Pfingst told his attorneys to go back over old murder and rape convictions and see if any unravel with newly developed DNA-testing tools. In other words, he wanted to revisit past victories — this time playing for the other team. " I think people misunderstand being conservative for being biased," says Pfingst. " I consider myself a pragmatic guy, and I have no interest in putting innocent people in jail. " Around the U. S. , flabbergasted defense attorneys and their jailed clients cheered his move. Among prosecutors, however, there was an awkward pause. After all, each DNA test costs as much as $5, 000. Then there's the unspoken risk: if dozens of innocents turn up, the D. A. will have indicted his shop. But nine months later, no budgets have been busted or prosecutors ousted. Only the rare case merits review. Pfingst's team considers convictions before 1993, when the city started routine DNA testing. They discard cases if the defendant has been released. Of the 560 remaining files, they have re-examined 200, looking for cases with biological evidence and defendants who still claim innocence. They have identified three so far. The most compelling involves a man serving 12 years for molesting a girl who was playing in his apartment. But others were there at the time. Police found a small drop of saliva on the victim's shirt — too small a sample to test in 1991. Today that spot could free a man. Test results are due any day. Inspired by San Diego, 10 other counties in the U. S. are starting DNA audits.

单选题Two techniques have recently been developed to simplify research and reduce the number of nonhuman primates needed in studies of certain complex hormonal reactions. One technique involves the culturing of primate pituitary cells and the cells of certain human turnouts. In the other, animal oviduct tissue is transplanted under the skin of laboratory primates. Both culturing techniques complement existing methods of studying intact animals. With an in vitro culturing technique, researchers are deciphering how biochemical agents regulate the secretion of prolactin, the pituitary hormone that promotes milk production. The cultured cells survive for as long as a month, and they do not require serum, a commonly used culture ingredient that can influence cellular function and confound study results. One primate pituitary gland may yield enough cells for as many as 72 culture dishes, which otherwise would require as many animals. The other technique allows scientists to monitor cellular differentiation in the reproductive tracts of female monkeys. While falling short of the long-sought goal of developing an in vitro model of the female reproductive system, the next-best alternative was achieved. The method involves transplanting oviduct tissue to an easily accessible site under the skin, where the grafted cells behave exactly as if they were in their normal environment. In about 80 percent of the grafts, blood vessels in surrounding abdominal skin grow into and begin nourishing the oviduct tissue. Otherwise, the tissue is largely isolated, walled off by the surrounding skin. A cyst forms that shrinks and swells in tandem with stages of the menstrual cycle. With about 80 percent of the grafts re-establishing themselves in the new site, a single monkey may bear as many as 20 miniature oviducts that are easily accessible for study. Because samples are removed with a simple procedure requiring only local anaesthesia, scientists can track changes in oviduct cells over short intervals. In contrast, repeated analysis of cellular changes within the oviduct itself would require abdominal surgery every time a sample was taken--a procedure that the animals could not tolerate. Scientists are using the grafting technique to study chlamydia infections, a leading cause of infertility among women. By infecting oviduct tissues transplanted into the abdominal skin of rhesus monkeys, researchers hope to determine how the bacteria cause pelvic inflammatory disease and lesions that obstruct the oviduct. Such research could eventually lead to the development of antibodies to the infectious agent and a strategy for producing a chlamydia vaccine.

单选题The creation of UN was, perhaps, the most ______ achievement of the 20th century.

单选题Some individuals, however, have strong moral and religious beliefs A that view abortionas an act of murder and B thus to believe that the C "right to life" of an unborn child should D take precedence over .

单选题The nurses in this hospital are most ______ of the patients.

单选题The effect of electric technology had at first been anxiety. Now it appears to create ______. A. bore B. bored C. boredom D. bordom

单选题Then felt like some watcher of the skies When a new planet swims into his ken, Or like stout Cortez, when with eagle eyes He stared at the Pacific--and all his men Looked at each other with a wild surmise-- Silent, upon a peak in Darien. --Keats With these well-loved lines John Keats recognized the most important geographical event in all the world, excepting only the feat of the Admiral Columbus himself. It was the discovery by European men of a vast sheet of water covering nearly 40 per cent of the globe--the ocean later to be named Pacific by Ferdinand Magellan because of its seeming tranquility. It is too bad that Keats' beautiful lines erred in naming stout Cortez instead of the equally stout Balboa, a hero of much courage and perseverance. Too bad it was, too, for the immortal Vasco Nunez de Balboa, that communications in his day were so slow and uncertain. Had they been better he might well have avoided losing his head for his pains in bringing renown to Spain and incalculable new knowledge to the civilized world. For lose it he did, under the axe at the insance of a jealous governor.

单选题______ a larger percentage of its gross national product on defending its coasts from rising seas than ______.

单选题She sounded so______that everyone present believed her story.(2011年华东师范大学试题)

单选题Initially his book did not receive much attention, but two weeks after the critic's review appeared in the newspapers, it climbed to the best sellers' list.

单选题The evolution of sex ratios has produced, in most plants and animals with separate sexes, approximately equal numbers of males and females. Why should this be so? Two main kinds of answers have been offered. One is couched in terms of advantage to population. It is argued that the sex ratio will evolve so as to maximize the number of meetings between individuals of the opposite sex. This is essentially a "group selection" argument. The other, and in my view correct, type of answer was first put forward by Fisher in 1930. This "genetic" argument starts from the assumption that genes can influence the relative numbers of male and female offspring produced by an individual carrying the genes. That sex ratio will be favored which maximizes the number of descendants an individual will have and hence the number of gene copies transmitted. Suppose that the population consisted mostly of females, then an individual who produced sons only would have more grandchildren. In contrast, if the population consisted mostly of males, it would pay to have daughters. If, however, the population consisted of equal numbers of males and females, sons and daughters would be equally valuable. Thus a one-to-one sex ratio is the only stable ratio; it is an "evolutionarily stable strategy". Although Fisher wrote before the mathematical theory of games had been developed, his theory incorporates the essential feature of a game that the best strategy to adopt depends on what others are doing. Since Fisher's time, it has been realized that genes can sometimes influence the chromosome or gamete in which they find themselves so that the gamete will be more likely to participate in fertilization. If such a gene occurs on a sex-determining(X or Y)chromo-some, then highly aberrant sex ratios can occur. But more immediately relevant to game theory are the sex ratios in certain parasitic wasp species that have a large excess of females. In these species, fertilized eggs develop into females and unfertilized eggs into males. A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized. By Fisher's argument, it should still pay a female to produce equal numbers of sons and daughters. Hamilton, noting that the eggs develop within their host —the larva of another insect — and that the newly emerged adult wasps mate immediately and disperse, offered a remarkably cogent analysis. Since only one female usually eggs in a given larva, it would pay her to produce one male only, because this one could fertilize all his sisters on emergence. Like Fisher, Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking strategy.

单选题More charity goods must be sent immediately to those African countries ______ by poverty and hunger.

单选题Her government, by its clear ______ with many previous policies, has placed a double strain on the traditional relationship.

单选题A ______ surgeon can be as dangerous as a recruit with a gun who does not know how to handle. A. professional B. negligent C. competent D. mellow

单选题Many animals are on the______of disappearing from the face of the earth and zoos can provide them with a safe place to live and breed.(2013年10月中国科学院考博试题)

单选题We shall probably never be able to______the exact nature of these sub-atomic particles.

单选题What kind of______. does the book have? Is it hard back or soft back?

单选题Some ______ good luck brought us nothing but trouble. A) seemingly B) satisfactorily C) uniformly D) universally

单选题{{B}}Passage One{{/B}} The table before which we sit may be, as the scientist maintains, composed of dancing atoms, but it does not reveal itself to us as anything of the kind, and it is not with dancing atoms but a solid and motionless object that we live. So remote is this "real" table—and most of the other "realities" with which science deals—that it cannot be discussed in terms which have any human value, and though it may receive out purely intellectual credence it cannot be woven into the pattern of life as it is led, in contradistinction to life as we attempt to think about it. Vibrations in the either are so totally unlike, let us say, the color purple that the gulf between them cannot be bridged, and they are, to all intents and purposes, not one but two separate things of which the second and less "real" must be the most significant for us. And just as the sensation which has led us to attribute an objective reality to a non-existent thing which we call "purple" is more important for human life than the conception of vibrations of a certain frequency, so too the belief in God, however ill founded, has been more important in the life of man than the germ theory of decay, however true the latter may be. We may, if we like, speak of consequence, as certain mystics love to do, of the different levels or orders of truth. We may adopt what is essentially a Platonist trick of thought and insist upon postulating the existence of external realities which correspond to the needs and modes of human feeling and which, so we may insist, have their being is some part of the universe unreachable by science. But to do so is to make an unwarrantable assumption and to be guilty of the metaphysical fallacy of failing to distinguish between a truth of feeling and that other sort of truth which is described as a "truth of correspondence," and it is better perhaps, at least for those of us who have grown up in an age of scientific thought, to steer clear of such confusions and to rest content with the admission that, though the universe with which science deals is the real universe, yet we do not and cannot have any but fleeting and imperfect contacts with it; that the most important part of our lives-our sensations, emotions, desires, and aspirations-takes place in a universe of illusions which science can attenuate or destroy, but which it is powerless to enrich.

单选题In the "New Horizon College English" course, students must take performance tests at monthly ______.