1、考研英语 648及答案解析(总分：36.00，做题时间：180 分钟)一、Section Use of (总题数：1，分数：1.00)The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, -|_|- this is largely because, -|_|- animals, we stand upright. This means that our noses are -|_|- to perceiving those
2、smells which float through the air, -|_|- the majority of smells which stick to surfaces. In fact, -|_|- , we are extremely sensitive to smells, -|_|- we do not generally realize it. Our noses are capable of -|_|- human smells even these are -|_|-to far below one part in one million. Strangely, some
3、 people find that they can smell one type of flower but not another, -|_|- others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate -|_|- smell receptors in the nose. These receptors are the cells which sense smells and send -|_|
4、- to the brain. However, it has been found that even people insensitive to a certain smell -|_|- can suddenly become sensitive to it -|_|- to it often enough. The explanation for insensitivity to smell seems to be that the brain finds it -|_|- to keep all smell receptors working all the time but can
5、 -|_|- new receptors if necessary. This may -|_|- explain why we are not usually sensitive to our own smellswe simply do not need to be. We are not -|_|- of the usual smell of our own house, but we -|_|- new smells we visit someone else s. The brain finds it best to keep smell receptors -|_|- for un
6、familiar and emergency signals -|_|- the smell of smoke, which might indicate the danger of fire. The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, -|_|- this is largely because, -|_|- animals, we stand upright. This means that our noses
7、 are -|_|- to perceiving those smells which float through the air, -|_|- the majority of smells which stick to surfaces. In fact, -|_|- , we are extremely sensitive to smells, -|_|- we do not generally realize it. Our noses are capable of -|_|- human smells even these are -|_|-to far below one part
8、in one million. Strangely, some people find that they can smell one type of flower but not another, -|_|- others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate -|_|- smell receptors in the nose. These receptors are the cells w
9、hich sense smells and send -|_|- to the brain. However, it has been found that even people insensitive to a certain smell -|_|- can suddenly become sensitive to it -|_|- to it often enough. The explanation for insensitivity to smell seems to be that the brain finds it -|_|- to keep all smell recepto
10、rs working all the time but can -|_|- new receptors if necessary. This may -|_|- explain why we are not usually sensitive to our own smellswe simply do not need to be. We are not -|_|- of the usual smell of our own house, but we -|_|- new smells we visit someone else s. The brain finds it best to ke
11、ep smell receptors -|_|- for unfamiliar and emergency signals -|_|- the smell of smoke, which might indicate the danger of fire. （分数：1.00）A.althoughB.asC.butD.while二、Section Writing(总题数：1，分数：1.00)2. (1) effect of the countrys growing human population on its wildlife (2) possible reason for the effec
12、t (3) your suggestion for wildlife protection (1) effect of the countrys growing human population on its wildlife (2) possible reason for the effect (3) your suggestion for wildlife protection* （分数：1.00）_三、Section Reading(总题数：4，分数：4.00)Non-indigenous (non-native) species of plants and animals arrive
13、 by way of two general types of pathways. First, species having origins outside the United States may enter the country and become established either as free-living populations or under human cultivation-for example, in agriculture, horticulture, aquaculture, or as pets. Some cultivated species subs
14、equently escape or are released and also become established as free-living populations. Second, species of either U.S. or foreign origin and already within the United States may spread to new locales. Pathways of both types include intentional as well as unintentional species transfers. Rates of spe
15、cies movement driven by human transformations of natural environments as well as by human mobility-through commerce, tourism, and travel-greatly exceed natural rates by comparison. While geographic distributions of species naturally expand or contract over historical time intervals (tens to hundreds
16、 of years), species ranges rarely expand thousands of miles or across physical barriers such as oceans or mountains. Habitat modification can create conditions favorable to the establishment of non-indigenous species. Soil disturbed in construction and agriculture is open for colonization by non-ind
17、igenous weeds, which in turn may provide habitats for the non-indigenous insects that evolved with them. Human-generated changes in fire frequency, grazing intensity, as well as soil stability and nutrient levels similarly facilitate the spread and establishment of non-indigenous plants. When human
18、changes to natural environments span large geographical areas, they effectively create passages for species movement between previously isolated locales. The rapid spread of the Russian wheat aphid to fifteen states in just two years following its 1986 arrival has been attributed in part to the prev
19、alence of alternative host plants that are available when wheat is not. Many of these are non- indigenous grasses recommended for planting on the forty million or more acres enrolled in the U.S. Department of Agriculture Conservation Reserve Program. A number of factors perplex quantitative evaluati
20、on of the relative importance of various entry pathways. Time lags often occur between establishment of non-indigenous species and their detection, and tracing the pathway for a long-established species is difficult. Experts estimate that non-indigenous weeds are usually detected only after having b
21、een in the country for thirty years or having spread to at least ten thousand acres. In addition, federal port inspection, although a major source of information on non-indigenous species pathways, especially for agriculture pests, provides data only when such species enter via closely-examined rout
22、es. Finally, some comparisons between pathways defy quantitative analysis-for example, which is more “important“: the entry path of one very harmful species or one by which many but less harmful species enter the country? （分数：1.00）(1).Which of the following statements about species movement is best
23、supported by the text?（分数：0.20）A.Human factors affect its rates more than its long-term amount.B.Natural expansions of species account for their slow contractions.C.Natural environments created by humans facilitate species movement.D.Long-range species movement relies on the ranges of mans mobility.
24、(2). According to the text, the U.S. Department of Agriculture（分数：0.20）A.is liable for the fast distribution of the Russian wheat pest.B.failed to isolate the Russian wheat aphid in limited locales.C.provides data about foreign species imported by regulated routes.D.is responsible for introducing ha
25、rmful plants onto federal lands.(3). Which of the following may best express the chief purpose of the last paragraph.?（分数：0.20）A.To explain the difficulties in tracing the pathways for long-established species.B.To describe the events leading to the detection of non-indigenous species.C.To identify
26、the problems in assessing the weight of entry tracks for foreign species.D.To discuss the role of time lags and geographic expansion in species detection.(4).It can be inferred that all of the following affect the movement of species EXCEPT（分数：0.20）A.earth fertility.B.import restrictions.C.natural o
27、bstacles.D.fire disasters.(5).To determine the entry pathway for a non-native species is LEAST likely to depend on（分数：0.20）A.whether the species is considered to be a pest.B.whether the species enters by a closely-checked route.C.the rate at which the species extends geographically.D.the magnitude o
28、f the average number of the species.Its hardly news anymore that Americans are just too fat. A quick look around the mall, the beach or the crowd at any baseball game will leave no room for doubt:our individual weight problems have become a national crisis. Even so, the actual numbers are shocking.
29、Fully two-thirds of U. S. adults are officially overweight, and about half of those have graduated to full-blown obesity. It wouldnt be such a big deal if the problem were simple aesthetic. But excess poundage takes a terrible toll on the human body. significantly increasing the risk of heart diseas
30、e, high blood pressure, diabetes, infertility, and many forms of cancer. The total medical bill for illnesses related to obesity is $117 billion a year-and climbing - and the Journal of the American Medical Association reported that poor diet and physical inactivity could soon overtake tobacco as th
31、e leading cause of preventable death in the U. S. Why is it happening? The obvious, almost trivial answer is that we eat too much high-calorie food and dont burn it off with enough exercise. If only we could change those habits, the problem would go away. But clearly it isnt that easy. Americans pou
32、r scores of billions of dollars every year into weight-loss products and health-club memberships. Food and drug companies spend even more trying to find a magic food or drug that will melt the pounds away. Yet the nations collective waistline just keeps growing. Its natural to try to find something
33、to blame - fast-food joints or food manufacturers or even ourselves for having too little willpower. But the ultimate reason for obesity may be rooted deep within our genes. Obedient to the inevitable laws of evolution, the human race adapted over millions of years to living in a world of scarcity,
34、where it paid to eat every good-tasting thing in sight when you could find it. Although our physiology has stayed pretty much the same for the past 50,000 years or so,we humans have utterly transformed our environment. Over the past century especially, technology has almost completely removed physic
35、al exercise from the day-to-day lives of most Americans. At the same time, it has filled supermarket shelves with cheap, mass-produced, good-tasting food that is packed with calories. And finally, technology has allowed advertisers to deliver constant, virtually irresistible messages that say “Eat t
36、his now“ to everyone old enough to watch TV. This artificial environment is most pervasive in the U. S. and other industrialized countries, and thats exactly where the fat crisis is most acute. （分数：1.00）(1). The author warns that overweight has（分数：0.20）A.become an obsolete source of news.B.been a co
37、mmon concern in the U. S.C.developed into a critical condition.D.grown into a threat to the nation.(2).The text arranges obesity according to（分数：0.20）A.class.B.size.C.grade.D.rank.(3). Fat crisis seems to result chiefly from（分数：0.20）A.failure to check fast food joints.B.super-affluent living conditi
38、ons.C.defects of most weight-loss drugs.D.variable eating habits of humans.(4).According to the 2nd paragraph,（分数：0.20）A.obese individuals appear simply unsightly.B.losing a pound of excess weight is very costly.C.obesity bears liability for most human deaths.D.overweight has appalling effect on our
39、 health.(5).All of the following directly account for obesity EXCLUDING（分数：0.20）A.most nourishing diet.B.less drain on strength.C.a lot of extra body fat.D.labor-saving technology.The Supreme Court s decisions on physician-assisted suicide carry important implications for how medicine seeks to relie
40、ve dying patients of pain and suffering. Although it ruled that there is no constitutional right to physician-assisted suicide, the Court in effect supported the medical principle of “double effect,“ a centuries-old moral principle holding that an action having two effectsa good one that is intended
41、 and a harmful one that is foreseenis permissible if the actor intends only the good effect. Doctors have used that principle in recent years to justify using high doses of morphine to control terminally iii patients pain, even though increasing dosages will eventually kill the patient. Nancy Dubler
42、, director of Montefiore Medical Center, contends that the principle will shield doctors who“ until now have very, very strongly insisted that they could not give patients sufficient medication to control their pain if that might hasten death.“ George Annas, chair of the health law department at Bos
43、ton University, maintains that, as long as a doctor prescribes a drug for a legitimate medical purpose, the doctor has done nothing illegal even if the patient uses the drug to hasten death. “Its like surgery,“ he says.“ We dont call those deaths homicides because the doctors didnt intend to kill th
44、eir patients, although they risked their death. If youre a physician, you can risk your patients suicide as long as you dont intend their suicide.“ On another level, many in the medical community acknowledge that the assisted-suicide debate has been fueled in part by the despair of patients for whom
45、 modern medicine has prolonged the physical agony of dying. Just three weeks before the Courts ruling on physician-assisted suicide, the National Academy of Science (NAS) released a two-volume report, Approaching Death: Improving Care at the End of Life. It identifies the undertreatment of pain and
46、the aggressive use of“ ineffectual and forced medical procedures that may prolong and even dishonor the period of dying“ as the twin problems of end-of-life care. The profession is taking steps to require young doctors to train in hospices, to test knowledge of aggressive pain management therapies,
47、to develop a Medicare billing code for hospital-based care, and to develop new standards for assessing and treating pain at the end of life. Annas says lawyers can play a key role in insisting that these well-meaning medical initiatives translate into better care.“ Large numbers of physicians seem unconcerned with the pain their patients are needlessly and predictably suffering,“ to the extent that it constitutes“ systematic patient ab
