托福-11及答案解析.doc

1、托福-11 及答案解析(总分：99.96，做题时间：90 分钟)一、READING(总题数：0，分数：0.00)二、passage-1(总题数：1，分数：12.00)HurricanesHurricanes are migratory tropical cycles that originate over water in certain regions near the equator, particularly over the Caribbean Sea and the Gulf of Mexico. Light breezes alternate here with frequent

2、periods of brisk squalls or stronger winds, as well as intermittent calms. A similar phenomenon occurs in the Western Pacific; these Pacific tropical storms are known as typhoons. Most hurricanes that affect the American continents originate in a narrow belt just north of the Equator called the dold

3、rums. A hurricane consists of high velocity winds blowing circularly around a low-pressure center, which is known as the eye of the hurricane. The low-pressure center develops when warm, saturated air common in the doldrums is under-run and forced upward by denser, cooler air. Hurricanes may be up t

4、o I50 miles in diameter, and gale winds may prevail over an area as large as 300 miles in diameter. As one moves from the edge of the storm towards the center, the pressure drops and the intensity of the wind increases. Meteorologists rank hurricanes on a scale of 1 to 5. The least severe category 1

5、 hurricanes have winds of at least 74 miles per hour, while the much stronger and rarer category 5 hurricanes have winds exceeding 155 miles per hour. Within the eye of the storm, the wind“s intensity is far more reduced and the clouds lift, yet the seas remain extremely violent underneath. The hurr

6、icane season varies in length according to its region of origin, although generally speaking it peaks worldwide at the end of the summer season in September, and wanes altogether during a brief period in May. That seasonal pattern is due to changes in surface water temperature. Thus, the difference

7、between ocean temperatures and atmospheric temperature is the greatest in the summer, which explains the unusual frequency of hurricanes during the upcoming month of September. However, regional variations in the onset and end of a hurricane season can be observed throughout the globe. In the Atlant

8、ic region, hurricanes occur typically from June to November, with a sharp peak in September. The Pacific hurricane season usually lasts all year round, although it records most activity in September and least power in February. In the Indian Ocean, the pattern shifts slightly from April to December,

9、 with an upsurge in May and November, whereas in the Southern Hemisphere the trend is from October to May with a spike in February or March. The National Hurricane Center is located in Florida and tracks each storm on a virtual map right from its beginning to its end. A system for tracking hurricane

10、s was developed in the 1950s and improvements have occurred periodically over the years. Scientists are now much more able to accurately make predictions regarding hurricanes, and this has helped minimize loss of life. However, scientists cannot stop hurricanes from developing altogether, and they c

11、ontinue to pose a threat, particularly in coastal regions. 1992“s Hurricane Andrew devastated large areas of Florida and the Caribbean leaving 50 dead, thousands homeless and causing property damage of approximately 12 billion dollars. While most hurricanes are not that severe, Andrew was a reminder

12、 that hurricanes have the capacity to wreak havoc and disrupt lives. Glossaryequator: a circle that divides a sphere or other surface into congruent parts doldrums: a region of the ocean near the equator, characterized by calms, light winds, or squalls diameter: a straight line segment passing throu

13、gh the center of a figure, especially of a circle or sphere, and terminating at the periphery reminder: a message that helps you remember something（分数：12.00）(1).According to the passage, what can be inferred about Hurricanes?（分数：3.00）A.Hurricanes may develop either over large swaths of land or over

14、wide bodies of water.B.Hurricanes can only develop within certain well-defined areas in the vicinity of the equator.C.While hurricanes may develop in certain low-pressure areas, they ultimately can start anywhere in the world.D.Hurricanes usually develop over certain well-defined areas that border t

15、he Pacific Ocean to the West.(2).What can be inferred from paragraph 6?（分数：3.00）A.It seems certain that modern technology will one day make hurricanes entirely preventable.B.Unfortunately, little is still known about what causes hurricanes, which makes combating them a rather daunting challenge.C.De

16、spite recent improvements in the detection of hurricanes, not much can be done to alter their destructive force.D.Due to the latest tracking systems, hurricanes are currently not as severe as they once were.(3).What can be inferred about Hurricane Andrew from the passage?（分数：3.00）A.Scientists consid

17、er it fairly typical in scope and sheer strength of most hurricanes that originate in that area.B.The path of destruction left behind in its wake was clue to the fact that it was not predicted by scientists.C.Scientists consider it an exception to the rule given its particularly forceful and destruc

18、tive nature.D.Scientists were able to learn a great deal about the nature and severity of hurricanes in the region by studying that particular hurricane.(4).What can be inferred about the hurricane season?（分数：3.00）A.Hurricanes are scattered throughout the world and occur randomly at various points i

19、n time, although September is a common hurricane month.B.The hurricane season can be anticipated with minute precision since it depends largely on the atmospheric pressure of each hemisphere.C.The hurricane period is very much predictable given the water-air temperature differential during certain s

20、easons.D.The hurricane season is very different from oceanic to oceanic region, although there are some inexplicable coincidences in September.三、passage-2(总题数：1，分数：12.00)BloodTo do its job properly, blood must travel continually around the body. The pumping heart forces blood around the circulatory

21、system to constantly change the fluid surrounding the living cells so that fresh supplies of oxygen and food are brought in as fast as they are used up and poisonous end-products are discarded. The arteries carry blood to every organ of the body, such as the liver, the stomach, the kidneys and the i

22、ntestines. The liver and kidneys play a vital role in the blood system. Many of the chemical activities carried out within the body result in toxic byproducts. These substances diffuse into the lymphatic system and are carried off into the plasma. When they eventually reach the kidneys, a large prop

23、ortion of this noxious waste is excreted through the outer organs. The blood passes regularly through the liver and kidneys, picking up nutrients from the former and recycling the waste through the latter. While the kidneys acts as a flushing device for food residues, the liver is mainly a storage s

24、ystem. Only a select amount of nutrients is transferred from the liver to the blood, depending on the body“s immediate need. The rest is stored in the liver until it becomes necessary. The arteries get smaller and smaller as they pass through the various organs and tissues. The smallest vessels are

25、the capillaries. It is through the thin walls of these capillaries that the body cells get their food and oxygen and release their waste. The capillaries join up again to form veins. Blood flows through the veins back to the heart. The arteries have much thicker wails than the veins to withstand the

26、 pressure of blood coining directly from the heart. There is little blood pressure in the veins. The action of the muscles of the body helps to massage blood through the veins, and the valves in the vein walls prevent blood in the veins from flowing the wrong way. When blood returns from the veins,

27、the heart pumps it to the lungs. There it gives up carbon dioxide and takes in oxygen. After being refreshed, the blood returns to the heart and is again pumped out to all parts of the body through the arteries. This double flow of fresh blood from the heart to various parts of the body, followed by

28、 the transfer of used blood first to the lungs then back to the heart, is called double circulation. The continuous double circulation of the blood system can be measured my means of external devices. Heart monitors are used to record a person“s systolic or diastolic pressure, as the two main compon

29、ents of the double circulation system are termed. There is a healthy range for each blood pressure measurement, which depends on an individual“s age, diet and activity. Strenuous activities are known to temporarily increase blood pressure above the usual top limit. Another sign of increased cardiova

30、scular activity is the bulging of the vein walls during exercise. Contrary to popular belief, this slight enlargement of the veins is not caused by higher blood pressure but rather by enzymatic activity. When more blood is pumped through the system, capillaries dilate and release enzymes to facilita

31、te better arterial flow. The enzymes get into the muscles, and this hardening of the muscles pushes the veins towards the skin giving them a bulging appearance. Glossarycirculatory: relating to circulatory system or to circulation of the blood plasma: the fluid part especially of blood lymph, or mil

32、k that is distinguished from suspended material capillary: one of the minute blood vessels that connect arterioles and venules artery: a blood vessel that carries blood from the heart to the body（分数：12.00）(1).Based on the information in paragraph 2, what can be inferred about the importance of the l

33、iver and kidneys in maintaining a healthy body?（分数：3.00）A.Liver and kidneys clear the body of toxic waste before it can do any harm to the entire blood system.B.The kidney is able to remove the excess fat stored and processed by the liver.C.The liver and kidney circulate nutrients and regulate chemi

34、cal processes in the body that create wasteful toxic end-products.D.The liver and kidney are both key factors in maintaining a healthy weight and an adequate energy level.(2).Based on the information in paragraph 3, what can be inferred about capillaries?（分数：3.00）A.Capillary walls serve as a gateway

35、 for the absorption of needed nutrients and the elimination of unnecessary residual products.B.Capillaries serve as a crucial joint in the formation of the vital arterial blood system.C.Capillaries resemble arteries in that they are lighter and more fragile than veins and cannot withstand the force

36、of the heart.D.Capillaries perform a lesser role than veins and arteries given their comparatively smaller size.(3).According to paragraph 3, what can be inferred about valves in the veins?（分数：3.00）A.Valves serve as filters for residues that deposit along the vein walls.B.Valves prevent the build-up

37、 of carbon dioxide by helping pump fresh blood more speedily along the veins.C.Valves act as key regulators and directors of correct blood flow.D.Valves facilitate the proper storage of oxygenized blood in cases of major importance.(4).Based on the information in paragraph 6, what can be inferred ab

38、out heavy exercise?（分数：3.00）A.When people get a lot of exercise, their veins become larger because more blood flows through them.B.When people get a lot of exercise, their veins become stronger and thicker, and more able to withstand blood pressure.C.When people get a lot of exercise, their veins be

39、come extended by the immediate release of depressurizing enzymes.D.When people get a lot of exercise, their veins become more evident because capillaries release enzymes into nearby muscles that press against the veins.四、passage-3(总题数：1，分数：12.00)GenesUntil only just a few centuries ago, people belie

40、ved that the genes of the parents blended together and resulted in the exact same genetic makeup. Then, in the early 1800s, Gregory Mendel, a renowned Austrian scientist, discovered that only certain traits such as the shape of the nose, or a particular eye color are passed directly from parent to c

41、hild. Because of his work, and the work of many scientists since, we now know that many of our physical and behavioral characteristics are determined by genetic factors which have been handed down to us from our parents and grandparents. We also know that our genes, as well as our lifestyle, are beh

42、ind many common diseases that afflict us as individuals. The genes we inherit from our parents program our development from conception to adulthood. In each cell, we have about 90,000 pairs of genes arranged on 23 pairs of chromosomes, one of the pair being maternal and the other being paternal. Alt

43、hough our brothers and sisters inherit genes from the same parents, the mixture of genes is slightly different in each sibling. It is the reason every organism is different. Each gene provides instructions to a cell to carry out a single chemical process; it also controls the growth and reproduction

44、 of multiple cells. Genes are thus responsible for the development of the embryo into a baby and a child, then eventually into an adult. Throughout our lives, genes control cell function and the repair and replacement of damaged or dead cells. Blood relatives have many genes in common, and these gen

45、es help to determine family physical characteristics and other traits. Most of these traits, such as the shape of the nose, are trivial and have no significant effect on health. Other traits, such as being abnormally short or tall, or having a tendency to be overweight, can be associated with an inc

46、reased risk of certain diseases. Some diseases, such as hemophilia and cystic fibrosis, are directly caused by a mutation in a single gene or a pair of genes. These rare diseases follow a predictable pattern of inheritance, and this means that families in which the gene is present can usually be giv

47、en clear, reliable information regarding the risk of the disease affecting their future offspring. Therefore, gene therapy holds great promise for the cure of diseases, and researchers will eventually come up with a way to regulate abnormal gene behavior without disrupting normal ones. Some, gene th

48、erapists have looked at viruses as a way to cure certain diseases. However, viruses replicate easily and move around the body to interact with other genes, so a virus that is used to cure hemophilia can replicate and enter an area where a tumor gene is located and stimulate it to cause a cancer. Gen

49、e therapy using bacterial DNA yields opposite results. More common than these genetic disorders are those in which genes, along with other factors, contribute to a family“s susceptibility to certain diseases. For example, some disorders, such as coronary artery disease, tend to run in families, but

50、lifestyle factors such as a high-fat diet, smoking, and lack of exercise also play a part in determining whether these diseases develop. In some diseases that have a genetic component, including asthma, environmental factors, such as living in a polluted area, also play a crucial role. Cancer is not