单选题This style of writing, incidentally, is suggestive of what is called the "newsreel technique" of John Dos Passos.

单选题One room schools, with all subjects being taught to all grades at the same time, simply ______ when better transportation permits specialized spaces and specialized teaching.(北京大学2011年试题)

单选题Almost overnight, Ames became a hero of environmentalists when his finding led to new and ______ bans on certain chemicals.

单选题Chlorine is a mainstay in most swimming pools in the United States, and is used to eradicate bacteria. A bacteria-free pool will usually ensure that swimmers won't contract a serious illness if they spend time in, and possibly ingest, the water. When chlorine is added to pool water, a chemical reaction occurs whereby the chlorine breaks down into a legion of chemicals that combine to kill bacteria that may be in water. These chemicals, specifically hypochlorous acid and hypochlorite ion, eliminate bacteria by annihilating and then oxidizing the abhorrent cells. When this chemical reaction occurs, the baeteria are rendered essentially harmless. This chemical reaction doesn't occur immediately — individual components within chlorine take varying amounts of time to interact with the bacteria, creating an almost time-release-type of kill in the pool water. Chlorine must be regularly replenished. As they react, the hypochlorous acid and hypochlorite ion combine to create a particular acceptable pH level in the pool water. A pH is a measure of the alkalinity and acidity present; a pH value of 7 represents a neutral value, and 7. 4 is the pH value of the human tear. The pH ratio must be regularly monitored to ensure a consistent optimum ram — one usually kept within the spectrum of 7 to 8 as measured by a reliable pH measuring kit. As the chemicals in chlorine complete their reactions, they break down and are no longer effective in keeping the pool water neutralized. Additional chlorine must be added to water at specific times. Outdoor pools that are in direct sunlight need to have water added more often because the chemical reaction time for chlorine is increased and its effectiveness is reduced in these conditions. Since the hypochlorite ion is an especially potent chemical capable of fading fabrics and paint, most people are meticulous about rinsing chlorine from potentially affected areas. Although chlorine is inexpensive and widely available, some people find the bleach smell to be repugnant and the distinct aroma present at many swimming pools to be overwhelming. These people may not be able to enjoy aquatic pursuits in those pools that employ chlorine as a cleansing agent. Other people may find that inhaling chlorine at the high levels present around some pools may be difficult to tolerate. Still others may experience skin irritation after swimming in a pool containing chlorine. Although there are other chemicals and compounds available to clean swimming pools, they may be prohibitively expensive or incapable of killing all types of bacteria present in the water.

单选题There is no question that the old style of air pollution could kill people. In one week following the infamous "peasouper" fog in December 1952, 4, 700 people died in London. Most of these people were elderly and already had heart or lung diseases. A series of these killer fogs eventually led to the British Parliament passing the Clean Air Act which restricted the burning of coal. Fortunately the effect of smog on the lungs is not so dramatic. Scientists have now conducted a number of laboratory experiments in which volunteers are exposed to ozone inside a steel chamber for a few hours. Even at quite low concentrations there is a reversible fall in lung function, an increase in the irritability of the lungs and evidence of airway inflammation (发炎). Although irritable and inflamed lungs are particularly seen in people with asthma (哮喘) and other lung diseases, these effects of ozone also occur in healthy subjects. Similar changes are also seen after exposure to nitrogen dioxide, although there is some disagreement about the concentration at which they occur. Other studies have found that people living in areas with high levels of pollution have more symptoms and worse lung function than those living in areas with clean air. Groups of children attending school camps show falls in lung function even at quite low concentrations of ozone. There is also a relationship between ozone levels and hospital admissions for asthma, both in North America and Australia. It is suspected that long-term exposure to smog may result in chronic bronchitis (支气管炎) and emphysema (肺气肿), but this has yet to be proven. Recently an association has been found between the levels of particles in the air and death rates in North American cities. The reason for this association is not understood and as yet there is no evidence this occurs in Australia. However, we do know that hazy days are associated with more asthma attacks in children.

单选题Don' tU meddle /Uin her affairs, and in fact, she can attack the problem and solve it quickly herself.

单选题The economy in this region has been stagnant for a long time and no signs of recovery have ______ till now. A. shown up B. kept up C. picked up D. made for

单选题You didn"t put on more clothes; otherwise you ______ cold.

单选题Pan of his general thrift is to be meticulous in verifying monthly expenses.

单选题To some people, the greatest pleasure of life is to spend their time at home watching TV and ______ their pets. A.stroking B.desiring C.modeling D.flattering

单选题Small, pink and very ugly. Hardly the qualities of a star, but they describe the deformed mouse that was the media darling at a recent science exhibition in Beijing. With a complex tissue structure in the shape of a human ear grafted on to its back, the rosy rodent was a stunning symbol of the serious strides China is making in the field of biotechnology. China is fast applying the latest life-science techniques learned from the West m aggressively pursue genome research. It's establishing its own centers of technical excellence to build a scientific base to compete directly with the United States and Europe. With a plentiful supply of smart young scientists at home and lots of interest abroad biotechnology is on the brink of a boom in China and in the view of foreign scientists, Beijing is playing a clever hand, maximizing the opportunities open to them. For the moment, the cooperation exists mostly with Europe and the U. S. But Asia's other biotech leaders, Japan, Singapore and Korea, also are recognizing China's potential as an attractive low-cost base to conduct research. These partnerships--and China's advancement in the field of biotechnology--could help benefit the rest of Asia: China's rapid progress in improving crop yields will address food-security concerns in the region. In addition, China is more likely to focus on developing cheap technology that its predominantly poor population--and those of other Asian countries--can afford. There remain, however, serious barriers to the development of a strong biotech industry. Among them are a poor domestic legal framework, weak enforcement of intellectual-property rights and loose adherence to international standards. China is a signatory of the International Bio Safety Protocol, which should mean adherence to global standards governing the conduct of field trims. But some observers are skeptical. "The regulations look good, but I haven't met one scientist who believes they are being fully adhered to," says a European science analyst. If shortcuts are taken, then some of the recent scientific achievements trumpeted in the official press may never make it to market. But no matter how strict lab tests are, other problems lie in wait. For example, there is a number of tasks it would take years to fulfill in the patents office, says one lawyer, leaving innovators with little protection if they take a product to market in China.

单选题Some women, particularly those over 35 years of age, seem to be more ______ more serious problems such as clots in veins if they smoke heavily.

单选题Archaeology as a profession faces two major problems. First.it is the poorest of the poor. Only paltry sums are available for excavating and even less is available for publishing the results and preserving the sites once excavated. Yet archaeologists deal with priceless objects every day. Second, there is the problem of illegal excavation, resulting in museum-quality pieces being sold to the highest bidder. I would like to make an outrageous suggestion that would at one stroke provide funds for archaeology and reduce the amount of illegal digging. I would propose that scientific archaeological expeditions and governmental authorities sell excavated artifacts on the open market Such sales would provide substantial funds for the excavation and preservation of archaeological sites and the publication of results. At the same time, they would break the illegal excavator's grip on the market, thereby decreasing the inducement to engage in illegal activities. You might object that professionals excavate to acquire knowledge, not money. Moreover, ancient artifacts are part of our global cultural heritage, which should be available for all to appreciate, not sold to the highest bidder. I agree. Sell nothing that has unique artistic merit or scientific value. But, you might reply, everything that comes out of the ground has scientific value. Here we part company. Theoretically, you may be correct in claming that every artifact has potential scientific value. Practically, you are wrong. I refer to the thousand pottery vessels and ancient lamps that are essentially duplicates of one another. In one small excavation in Cyprus, archaeologists recently uncovered 2000 virtually indistinguishable small jugs in a single courtyard. Even precious royal seal impressions known as 1' melekh handles have been found in a-bundance------more than 4000 examples so far. The basements of museums are simply not large enough to store the artifacts that are likely to be discovered in the future. There is not enough money even to catalogue the finds;as a result, hey cannot be found a-gain and become as inaccessible as if they had never been discovered Indeed, with the help of a computer, sold artifacts could be more accessible than are the pieces stored in bulging museum basements. Prior to sale, each could be photographed and the list of the purchasers could be maintained on the computer. A purchaser could even be required to agree to return the piece if it should become needed for scientific purposes.

单选题The most convincing evidence for the importance of adult influence on a child's intelligence comes from a study of "at risk" children. Ramey and Frances Campbell of the University of North Carolina 61 with children born into poverty-line households. The children entered the study by four months 62 age. During the study, one group spent the day in a center where teachers used games and songs to 63 the infants. Another group had no such 64 , but they were given nutritional supplements in 65 . During preschool years the children in the early-education group showed IQ advantages often to 20 points. The highest-risk children showed the 66 gains, and at age 15 they had higher reading and math scores. What 67 for these gains? Ramey and other scientists say early childhood experiences 68 brain growth. An infant is bom 69 billions of brain cells called neurons. Some are wired to other cells before birth to regulate the 70 of life, such as heartbeat and breathing. Others are waiting to be wired to 71 him or her interpret and respond to the outside world. Experience dictates the hookups. As the child 72 , cells reach out and set up pathways to other cells needed to determine a 73 . For instance, the neurons in the eye send branches to the 74 cortex, which interprets 75 eye sees and, via other branches, 76 the person to react to what is seen. Each time an experience is repeated, the 77 are strengthened. The first two years of life are an explosion of brain 78 and connections. By age two the 79 has more than 300 trillion connections. At the same time, cells that aren't being connected or used are being 80 .

单选题 4 Linguists have understood for decades that language and thought are closely relat- ed. Humans construct reality using thought and express these thoughts through the use of language. Edward Sapir and his student Benjamin Whorl are credited with developing the most relevant explanation outlining the relationship between thought and language, the Sapir-Whorf Hypothesis. The hypothesis consists of two parts, linguistic relativity and lin guistic determinism. Supporters of linguistic relativity assume that culture is shaped by lan guage. Terwilliger defines linguistic determinism as the process by which "the functions of one's mind are determined by the nature of the language which one speaks. " In simpler terms, the thoughts that we construct are based upon the language that we speak and the words that we use. In its strongest sense, linguistic determinism can be interpreted as meaning that language determines thought. In its weakest sense, language partially influ ences thought. Whorl was careful to avoid authoritative statements which would perma nently commit him to particular position. Because of the broad nature of his statements, it is difficult to distinguish exactly to what extent Whorl believes that language determines thought. Heated debate among mod ern linguists demonstrates that disagreement exists about the accuracy and correctness of Whorf's studies and of the actual level of influence of language on thought processes. The Sapir-Whorf Hypothesis essentially consists of two distinct statements connecting the relation of thought and language. Whorl believes that humans may be able to think only about objects, processes, and conditions that have language associated with them. The Sapir-Whorf Hypothesis also explains the relationship between different languages (French, English, German, Chinese, and so on) and thought. Whorl demonstrated that culture is largely determined by language. Different cultures perceive the world in different ways. Culturally essential objects, conditions and processes usually are defined by a pleth ora of words, while things that cultures perceive as unimportant are usually assigned one or two words. Whorl developed this theory while studying the Hopi Indian tribe. Whorl was amazed that the Hopi language has no words for past, present, and future. The Hopi have only one word for flying objects. A dragonfly, an airplane, and a pilot are defined using the same word. Whorl questioned whether or not the Hopi view the world differently than western peoples. After further interpretation and analysis he concluded that the Hopi have a sense for the continuum of time despite having no words to specifically describe past, present, and future. It is commonly believed that the Sapir-Whorf Hypothesis possesses some truth, but the extent to which it is applicable to all situations is questioned. Linguists generally sup port a "strong" or a "weak" interpretation. Linguists who study the hypothesis tend to cite examples that support their beliefs but are unable or unwilling to refute the opposing arguments. Examples exist that strengthen the arguments of everyone who studies the hy pothesis. Nobody has gained significant ground in proving or refuting the hypothesis be cause the definitions of Sapir and Whorl are very vague and incomplete, leaving room for a significant amount of interpretation.

单选题The United States was trying hard to smoke the enemy out of the holesin the target country．

单选题______ students should be motivated by a keen interest in theatre and should have some familiarity with plays in production.