单选题Virtually everything astronomers know about objects outside the solar system is based on the detection of photons-quanta of electromagnetic radiation. Yet there is another form of radiation that permeates the universe: neutrinos. With (as its name implies) no electric charge, and negligible mass, the neutrino interacts with other particles so rarely that a neutrino can cross the entire universe, even traversing substantial aggregations of matter, without being absorbed or even deflected. Neutrinos can thus escape from regions of space where light and other kinds of electromagnetic radiation are blocked by matter. Not a single, validated observation of an extraterrestrial neutrino has so far been produced despite the construction of a string of elaborate observatories, mounted on the earth from Southern India to Utah to South Africa. However, the detection of extraterrestrial neutrinos are of great significance in the study of astronomy. Neutrinos carry with Their information about the site and circumstances of their production; therefore, the detection of cosmic neutrinos could provide new information about a wide variety of cosmic phenomena and about the history of the universe. How can scientists detect a particle that interacts so infrequently with other matter? Twenty-five years passed between Pauli's hypothesis that the neutrino existed and its actual detection; since then virtually all research with neutrinos has been with neutrinos created artificially in large particle accelerators and studied under neutrino microscopes. But a neutrino telescope, capable of detecting cosmic neutrinos, is difficult to construct. No apparatus can detect neutrinos unless it is extremely massive, because great mass is synonymous with huge numbers of nucleons (neutrons and protons), and the more massive the detector, the greater the probability of one of its nucleon's reacting with a neutrino. In addition, the apparatus must be sufficiently shielded from the interfering effects of other particles. Fortunately, a group of astrophysicists has proposed a means of detecting cosmic neutrinos by harnessing the mass of the ocean. Named DUMAND, for Deep Underwater Muon and Neutrino Detector, the project calls for placing an array of light sensors at a depth of five kilometers under the ocean surface. The detecting medium is the sea water itself: when a neutrino interacts with a particle in an atom of seawater, the result is a cascade of electrically charged particles and a flash of light that can be detected by the sensors. The five kilometers of seawater above the sensors will shield them from the interfering effects of other high-energy particles raining down through the atmosphere. The strongest motivation for the DUMAND project is that it will exploit an important source of information about the universe. The extension of astronomy from visible light to radio waves to x-rays and gamma rays never failed to lead to the discovery of unusual objects such as radio galaxies, quasars, and pulsars. Each of these discoveries came as a surprise. Neutrino astronomy will doubtlessly bring its own share of surprises.

单选题He told us that John, as well as his brother, ______ coming to the party. A. is B. are C. were D. was

单选题Which of the following is NOT correct according to the third paragraph?

单选题The study of literary influence among women writers has frequently adopted a model of sororal or matrilineal sharing in an often explicitly stated contrast to Harold Bloom's well-established theory of the "anxiety of influence" besetting male writers. In Bloom's powerfully influential vision, that anxiety is posed as a kind of Freudian agon of sons against fathers, a struggle of self-definition through resistance and mastery. Feminist critics have generally agreed with the Bloomian model as applied to male authors but have demurred with respect to women writers, whom we have tended to see in familial terms. The model of a separate women's tradition in literature, its inner coherence maintained by resistance to male dominance, that was posited in the 1970s by Ellen Moers, Elaine Showalter, and Sandra M. Gilbert and Susan Gubar has been widely accepted. As Betsy Erkkila points out, these groundbreaking feminist critics may not have significantly challenged the Bloomian model as applied to women writers and women precursors, but they did at any rate establish their resistance to the masculine literary establishment and the masculine model of rivalry. Their successors and elaborators have argued forcefully that a women's tradition is constituted of a supportive community whose members welcome the all-too-rare voices of foremothers calling to them across the ages. Even the literary foremothers nearer at hand, according to this prevailing vision, have served as models for emulation rather than hegemonic powers to be challenged. Erkkila, for example, asks pointedly, "How useful is the Bloomian model when the poet attempts to define herself not in relation to her poetic fathers but in relation to her poetic mothers." Her answer (later modified because of greater complexity) is not very. A metaphor of motherhood and daughterhood has, in the words of Linda R. Williams's recent revisionist theory, "profoundly affected our reading of women's literary history." Citing Alice Walker's argument about nebulous forms of knowing in In Search of Our Mothers' Gardens, Luce Irigary's concept of connectedness ( "One doesn't stir without the other") and Helene Cixous's version of the authentic woman writer's writing of her mother's milk in "The Laugh of the Medusa," Williams calls for an interpretation of literary connectedness not as a revision of the Freudian and Bloomian system-which Erkkila, by retaining the familial language, has in a sense retained, but as a way "outside of an Oedipal dynamic" altogether. The revisionist views of Williams and Erkkila are useful corrections of the prevailing mode of feminist theories that "romanticize, maternalize, essentialize, and eternalize women writers and the relationships among them." Neither, however, asks if women writers may not sometimes exhibit, rather than either revise or escape, the Bloomian model of literary rivalry. It is a prospect, perhaps, that we would prefer not to entertain. But it is a prospect that, while clearly not typical, may be less atypical than feminist critics may have supposed in our times too idealizing and essentializing theories. An instance of such a female adoption (and adaptation) of the Bloomian model of male writers' anxiety is Katherine Anne Porter's anxious and artfully duplicitous essay on a literary elder sister, "Reflections on Willa Cather." Operating in the loosely narrative fashion that characterized not only Porter's nonfiction but her very mode of thought, the essay purports to pay retrospective tribute to one of the preeminent women writers of the early and mid-twentieth century, but in fact asserts Porter's own stature in the world of letters. In the story of her essay, the protagonist is not Cather, as one would expect from the title, but Porter herself. The essay is cast in a pervasive first-person mode in which the observing or commenting "I" becomes the active principle and its putative topic a passive reflector, a mirror reflecting Katherine Anne Porter.

单选题The statistical figures in that report are not ______. You should not refer to them. A. accurate B. fixed C. delicate D. rigid

单选题She was between two very fat women and felt extremely uneasy, ______.

单选题 A. league B. tongue C. guess D. guest

单选题Radiation occurs from three natural sources: radioactive material in the environment such as in soil, rock, or building materials; cosmic rays; and substances in the human body, such as radioactive potassium in bones and radioactive carbon in tissues. These natural sources account for an exposure of about 100 millirems a year for the average American. The Iargcst single source of man-made radiation is medical X rays, yet most scientists agree that hazards from this source are not as great as those from weapons test fallout, since strontium 90 and carbon 14 become incorporated into the body, hence delivering radiation for an entire life- time. The issue is, however, by no means uncontroversial; the last two decades have witnessed intensified examination and dispute about the effects of low-level radiation, beginning with the United Nations Scientific Committee on the Effects of Atomic Radiation, which reported in 1958: "Even the smallest amounts of radiation are liable to cause deleterious genetic and perhaps also somatic effects." A survey conducted in Britain confirmed that an abnormally high percentage of patients suffering from arthritis of the spine who had been treated with X rays contracted cancer. Another study revealed a high incidence of childhood cancer in eases where the mother had been given prenatal pelvic X rays. These studies have pointed to the need to reexamine the assumption that exposure to low-linear energy transfer presents only a minor risk. Recently, examination of the death certificates of former employees of a West Coast plant which produces plutonium for nuclear weapons revealed markedly higher rates for cancers of the pancreas, lung, bone marrow, and lymph systems than would have been expected in a normal population. While the National Academy of Sciences Committee attributes this difference to chemical or other environmental causes rather than radiation, other scientists maintain that any radiation expo- sure, no matter how small, leads to an increase in cancer risk. It is believed by some that a dose of one rem, if sustained over many generations, would lead to an increase of 1 percent in the number of serious genetic defects at birth, a possible increase of 1,000 disorders per million births. In the meantime, regulatory efforts have been disorganized, fragmented, inconsistent, and characterized by internecine strife and bureaucratic delays. A Senate report concluded that coordination of regulation among involved departments and agencies was not possible because of jurisdictional disputes and confusion. One federal agency has been unsuccessful in its efforts to obtain sufficient funding and manpower for the enforcement of existing radiation laws, and the chairperson of a panel especially created to develop a coordinated federal program has resigned.

单选题The shorter working week, longer holidays, earlier retirement, more sabbaticals, job sharing these and other ways of reducing the amount of time people spend on their jobs are certainly likely to spread.

单选题The ministry announced at a State Council Information Office press conference on August 11 that 47 medical teams, with 779 members, were in Zhouqu treating patients, sterilizing the environment and drinking water, and ensuring proper disposal of corpses.

单选题The children glanced ______ at the box of candy they were told not to touch.

单选题We are taught that a business letter should be written in a formal style ______ in a personal one. A. rather than B. other than C. better than D. less than

单选题The playwright"s parliamentary career was notable for his eloquent speeches made in opposition to the British war against the American colonies, in support of the new French Republic, and in denunciation of the British colonial administrator Warren Hastings.

单选题We've done once but failed. We'll have to do it ______ time. A. a second B. the second C. the twice D. twice

单选题How would you describe the writer's attitude toward Karaoke? A. She often goes, and likes it sometimes and sometimes not. B. She thinks it is not only fun, but stress relieving as well. C. She has not tried it herself so has no attitude about it. D. She feels it is a waste of time.

单选题There is no creature that does not need sleep or complete rest every day. If you want to know why, just try going without sleep for a long period of time. You will discover that your mind and body would become too tired to work properly. You would become irritable and find it hard to think clearly or concentrate on your work. So sleep is quite simply the time when the cells of your body recover from the work of the day and build up supplies of energy for the next period of activity. One of the things we all know about sleep is that we are unconscious in sleep. We do not know what is going on around us. But that doesn' t mean the body stops all activity. The important organs continue to work during sleep, but most of the body functions are slowed down. For example, our breathing becomes slower and deeper. The heart beats more slowly, and the blood pressure is lower. Our arms and legs become limp(柔软的) and muscles are at rest. It would be impossible for our body to relax to such an extent if we were awake. So sleep does for us what the most quiet rest can not do. Your body temperature becomes lower when you are asleep, which is the reason people go to sleep under some kind of covers. And even though you are unconscious, many of your reflexes(反射 动作) still work. For instance, if someone tickles(使觉得痒) your foot, you will put it away in your sleep, or even brush a fly from your forehead. You do these things without knowing it.

单选题—He hasn't gone to the office up to now. —Well, he ______.A. shouldB. ought toC. ought to goD. ought to have