1、大学英语四级模拟试卷 617及答案与解析 一、 Part I Writing (30 minutes) 1 For this part, you are allowed 30 minutes to write a short essay entitled How to Relieve Stress. You should write at least 120 words according to the outline given below. 1现代人面临着各种压力 2人们减压的方法 各异 3我的减压方法 How to Relieve Stress 二、 Part II Reading Co
2、mprehension (Skimming and Scanning) (15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions attached to the passage. For questions 1-7, mark： Y (for YES) if the statement agrees with the information given in the passage; N (for NO) if t
3、he statement contradicts the information given in the passage; NG (for NOT GIVEN) if the information is not given in the passage. 1 The Human Brain The brain is the most complex organ in human body. It produces our every thought, action, memory, feeling and experience of the world. This jelly-like m
4、ass of tissue, weighing in around 1.4 kilograms, contains a staggering one hundred billion nerve cells, or neurons (神经元 ). The complexity of the connectivity between these cells is mind-boggling (令人难以置信的 ). Each neuron can make contact with thousands or even tens of thousands of others, via tiny str
5、uctures called synapses (突触 ). Our brains form a million new connections for every second of our lives. The pattern and strength of the connections is constantly changing and no two brains are alike. It is in these changing connections that memories are stored, habits learned and personalities shape
6、d, by reinforcing certain patterns of brain activities, and losing others. Grey Matter and White Matter While people often speak of their “grey matter“, the brain also contains white matter. The grey matter is the cell bodies of the neurons, while the white matter is the branching network of threadl
7、ike tendrils called dendrites and axons that spread out from the cell bodies to connect to other neurons. But the brain also has another, even more numerous type of cell, called glial (神 经胶质的 ) cells. These outnumber neurons over ten times. Once thought to be support cells, they are now known to amp
8、lify neural signals and to be as important as neurons in mental calculations. There are many different types of neuron, only one of which is unique to humans and the other great apes, the so-called spindle cells. Brain structure is shaped partly by genes, but largely by experience. Only recently it
9、was discovered that new brain cells are being born throughout our lives a process called neurogenesis. The brain has bursts of growth and then periods of consolidation, when excess connections are removed. The most notable bursts are in the first two or three years of life, during puberty, and also
10、a final burst in young adulthood. How a brain ages also depends on genes and lifestyle too. Exercising the brain and giving it the right diet can be just as important as it is for the rest of the body. Chemical Messengers The neurons in our brains communicate in a variety of ways. Signals pass betwe
11、en them by the release and capture of neurotransmitter and neuromodulator chemicals, such as glutamate, dopamine, acetylcholine, noradrenalin, serotonin and endorphins. Some neurochemicals work in the synapse, passing specific messages from release sites to collection sites, called receptors. Others
12、 also spread their influence more widely, like a radio signal, making whole brain regions more or less sensitive. These neurochemicals are so important that deficiencies in them are linked to certain diseases. For example, a loss of dopamine in the basal ganglia (基底神经节 ), which controls movements, l
13、eads to Parkinsons disease. It can also increase susceptibility to addiction because it mediates our sensations of reward and pleasure. Similarly, a deficiency in serotonin, used by regions involved in emotion, can be linked to depression or mood disorders, and the loss of acetylcholine in the cereb
14、ral cortex (大脑皮层 ) is characteristic of Alzheimers disease. Brain Scanning Within individual neurons, signals are formed by electrochemical pulses. Collectively, this electrical activity can be detected outside the scalp by an electroencephalogram (EEG). These signals have wave-like patterns, which
15、scientists classify from alpha (common while we are relaxing or sleeping), through to gamma (active thought). When this activity goes awry (错误 的 ), it is called a seizure. Some researchers think that synchronising the activity in different brain regions is important in perception. Other ways of imag
16、ing brain activity are indirect. Functional magnetic resonance imaging (fMRI) or positron emission tomography (PET) monitors blood flow. MRI scans, computed tomography (CT) scans and diffusion tensor images (DTI) use the magnetic signatures of different tissues, X-ray absorption, or the movement of
17、water molecules in those tissues, to image the brain. These scanning techniques have revealed which parts of the brain are associated with which functions. Examples include activities related to sensations, movement, libido, choices, regrets, motivations and even racism. However, some experts argue
18、that we put too much trust in these results and that they raise privacy issues. Before scanning techniques were common, researchers relied on patients with brain damage caused by strokes, head injuries or illnesses, to determine which brain areas are required for certain functions. Some Structures i
19、n Mind The most obvious anatomical feature of our brains is the undulating surface of the cerebrum (大脑 ) the deep clefts are known as sulci and its folds are gyri. The cerebrum is the largest part of our brain and is largely made up of the two cerebral hemispheres. It is the most evolutionarily rece
20、nt brain structure, dealing with more complex cognitive brain activities. It is often said that the right hemisphere is more creative and emotional while the left deals with logic, but the reality is more complex. Nonetheless, the sides do have some specialization, with the left dealing with speech
21、and language, the right with spatial and body awareness. Behind the ears and temples lie the temporal lobes (颞叶 ), dealing with sound and speech comprehension and some aspects of memory. And to the fore are the frontal and prefrontal lobes (额和额前叶 ), often considered the most highly developed and mos
22、t “human“ of regions, dealing with the most complex thought, decision making, planning, conceptualizing, attention control and working memory. They also deal with complex social emotions such as regret, morality and empathy. Another way to classify the regions is as sensory cortex and motor cortex,
23、controlling incoming information, and outgoing behavior respectively. Below the cerebral hemispheres, but still referred to as part of the forebrain, is the cingulated (扣 带 ) cortex, which deals with directing behavior and pain. And beneath this lies the corpus callosum (胼胝体 ), which connects the tw
24、o sides of the brain. Other important areas of the forebrain are the basal ganglia, responsible for movement, motivation and reward. The back of the brain has a highly convoluted and folded swelling called the cerebellum, which stores patterns of movement, habits and repeated tasks things we can do
25、without thinking about them. The most primitive parts, the midbrain and brain stem, control the bodily functions we have no conscious control of, such as breathing, heart rate, blood pressure, sleep patterns, and so on. They also control signals that pass between the brain and the rest of the body,
26、through the spinal cord. 2 Where are memories stored? （ A） In the nerve cell bodies. （ B） In the synapses. （ C） In neuron connections. （ D） In connection patterns. 3 What do we know about glial cells? （ A） They are much more than neurons. （ B） They are only support cells. （ C） They send neural signa
27、ls. （ D） They are unique to humans. 4 Neurogenesis occurs_. （ A） in our whole life （ B） when excess connections are pruned （ C） in three short periods （ D） when the brain is exercised 5 How do the neurons in our brains communicate with each other? （ A） They communicate by linking to the basal gangli
28、a. （ B） They work in the synapse to pass messages. （ C） They spread their influence like a radio signal. （ D） They release and capture neurochemicals. 6 What do we know about the brain scanning technology according to the passage? （ A） EEG is a direct way, and fMRI, MRI, CT and DTI are indirect. （ B
29、） EEG and fMRI are direct ways, and MRI, CT, and DTI are indirect. （ C） EEG, fMRI, MRI, CT and DTI are all indirect ways. （ D） EEG, fMRI, MRI, CT and DTI are all direct ways. 7 How did researchers find functions of the brain parts when scanning techniques were uncommon? （ A） They measured temperatur
30、es of different areas of the scalp. （ B） They used drugs to control different parts of the brain. （ C） They studied patients who had brain damage. （ D） They studied other great apes to make guesses. 8 The right hemisphere of the cerebrum_. （ A） has a more undulating surface than the left （ B） is mor
31、e evolutionarily advanced than the left （ C） deals with logic and language （ D） deals with spatial and body awareness 9 We often consider_as more advanced than other parts of the brain. 10 The corpus callosum lies beneath_. 11 Breathing and heart rate are controlled by_. Section A Directions: In thi
32、s section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must r
33、ead the four choices marked A, B, C and D, and decide which is the best answer. （ A） She has already had a job offer. （ B） She will line up to apply for a job. （ C） Shell look for a job soon after graduation. （ D） She hopes to get a job offer before graduation. （ A） Producing the same suits as other
34、 companies. （ B） Doing the same as other companies have done. （ C） Fighting against others by cutting down the cost. （ D） Working out other policies to compensate for the loss. （ A） She will live a simple life. （ B） She will fully focus on her job. （ C） She will quit her job to get married. （ D） She
35、 will stay with someone unmarried. （ A） Driving to work is really a headache. （ B） The woman will be able to buy an intelligent car. （ C） Cars that drive themselves may be very expensive. （ D） He is working with a car producer on intelligent cars. （ A） The man must be an excellent student. （ B） The
36、mans idea is probably a good one. （ C） The man had better drop more than one course. （ D） The man would not have dropped the best course of the four. （ A） Julies dress is not outdated. （ B） Julie looks fine in that dress. （ C） Julies dress does not suit her. （ D） Julie should follow the fashion. （ A
37、） He wont vote for the woman. （ B） He may also run for class president. （ C） He should promise to support the woman. （ D） The woman should ask his roommate to vote for her. （ A） She agrees to move the item to the balcony. （ B） She disagrees and wants the issue discussed now. （ C） She disagrees and w
38、ants the issue resolved immediately. （ D） She agrees but wants the issue to be further discussed later. Questions 19 to 22 are based on the conversation you have just heard. （ A） He was late for registration. （ B） He wants the professor to give him a mark. （ C） He cannot do well because the class is
39、 too large. （ D） He needs the permission of Professor Day to register. （ A） The student likes the course very much. （ B） Students attend it because it is required. （ C） The professor offers the course every term. （ D） It is so popular that students line up to get registered. （ A） Let the student att
40、end another class. （ B） Allow the student to take the class this term. （ C） Allow the student to take the class next year. （ D） Permit the student to graduate without the class. （ A） If you are punctual. （ B） If you are not lying on your CV. （ C） If you are experienced. （ D） If you have good communi
41、cation skills. （ A） You will not get the job. （ B） It perhaps has no influence on your getting the job. （ C） You will appear inarticulate. （ D） The interviewer will check your CV for the answer. （ A） People with such skills save them time and money. （ B） People with such skills are more experienced.
42、 （ C） People with such skills are usually better educated. （ D） People with such skills are more efficient at work. （ A） Your CV and appearance. （ B） Qualifications and experience. （ C） Communication skills and your personality. （ D） Cross-cultural communication skills. Section B Directions: In this
43、 section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D. （ A） He was silent most of the time.
44、 （ B） He was too proud of himself. （ C） He did not love his children. （ D） He expected too much of her. （ A） Nervous. （ B） Sorry. （ C） Tired. （ D） Safe. （ A） More critical. （ B） More talkative. （ C） Gentle and friendly. （ D） Strict and hard-working. （ A） One hundred dollars. （ B） Two hundred dollars
45、. （ C） Three hundred dollars. （ D） Four hundred dollars. （ A） Buy lottery tickets. （ B） Make use of half-truths. （ C） Not take anything at face value. （ D） Not trust the Yucky Company. （ A） Advertisements are based on facts. （ B） Doctors like to act in advertisements. （ C） False statements are easy
46、to see through. （ D） Half-truths are often used to mislead people. （ A） To learn to recognize plants and animals. （ B） To set up a tent and learn how to cook by yourself. （ C） To get to know more about yourself and your place in nature. （ D） To learn how to make use of a map to find your way in the
47、open air. （ A） Work and worries. （ B） A simpler lifestyle. （ C） Wilderness and animals. （ D） Canoes and camp grounds. （ A） To water the plants. （ B） To feed the animals. （ C） To take adventure alone. （ D） To treat nature with respect. （ A） To advocate a simple lifestyle. （ B） To encourage people to
48、become camp lovers. （ C） To explore the natural world as much as possible. （ D） To protect the nature while enjoying the plants and animals. Section C Directions: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its ge
49、neral idea. When the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just heard. For blanks numbered from 44 to 46 you are required to fill in the missing information. For these blanks, you can either use the exact words you have just heard or write down the 36 Agricultural experts have launched a land and water management project in the Middle East. The project seeks to increase food【 B1】 _in dry areas. Researchers say the wa
