1、大学英语四级模拟试卷 754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 On Training Classes. You should write at least 120 words following the outline given below: 1社会上有各种各样的培训班 2该现象产生的原因 3我的看法 On Training Classes 二、 Part II Reading Comprehensi
2、on (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 the statem
3、ent 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 mass of ti
4、ssue, 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 structures c
5、alled 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 shaped, by re
6、inforcing 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 thread-like ten
7、drils 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 ) ceils. These outnumber neurons over ten times. Once thought to be support cells, they are now known to amplify neu
8、ral 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 was disc
9、overed 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 a final
10、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 between them
11、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 also sp
12、read 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 (神经中枢 ), which controls movements, leads to P
13、arkinsons 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 cerebral corte
14、x (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 scientist
15、s 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 imaging brain a
16、ctivity 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 water molecu
17、les 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 that we put
18、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 in Mind The m
19、ost 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 recent brain str
20、ucture, 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 and language,
21、 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 most “human“ of
22、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, controlling i
23、ncoming 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, which connects the two sides of the brain.
24、 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 without thinking abou
25、t 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, through the spinal co
26、rd. 2 Where are memories stbred? （ 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 ceils? （ A） They are much more than neurons. （ B） They are only support cells. （ C） They send neural signals. （ D） They are uni
27、que 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 ganglia. （ B） They work in
28、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） EEG and fMRI are di
29、rect ways, and fMRI, 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 temperatures of different area
30、s 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 more evolutionarily adva
31、nced 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 this section, you will
32、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 read the four choices
33、 marked A, B, C and D, and decide which is the best answer. （ A） Professors lecture is boring but crucial. （ B） Its not necessary for the man to attend the lecture. （ C） The man should have been more attentive in the lecture. （ D） Professors lecture has nothing to do with the final exam. （ A） Hed be
34、tter submit his resume at once. （ B） Not all applicants will be interviewed. （ C） She does need his help for the moment. （ D） There might not be any interview at all. （ A） The man wants to be a business manager. （ B） The woman is working in a kindergarten. （ C） The woman is not happy with the mans d
35、ecision. （ D） The man will go in for business right after high school. （ A） Lend her his hiking shoes. （ B） Be more flexible. （ C） Lend her his gym shoes. （ D） Take more exercise. （ A） The woman paid only $ 120 on her books. （ B） Joanna saves a lot of money on textbooks. （ C） The man doesnt think te
36、xtbooks are expensive. （ D） Many students find useful books in the bookstore. （ A） He should try a different field of work. （ B） He should quit his job as soon as possible. （ C） He should find a more promising position. （ D） He should be more positive toward his work. （ A） He doesnt enjoy the dishes
37、 at Hilton. （ B） He believes the woman is not serious. （ C） He isnt familiar with the way to Hilton. （ D） He thinks dining at Hilton is not worthwhile. （ A） He has no experience at all. （ B） He has a charming personality. （ C） He is so lucky that he got the job. （ D） There were so many applicants. （
38、 A） Peaceful. （ B） Noisy. （ C） Tiring. （ D） Exhausting. （ A） Their recent situations. （ B） The beautiful views in fall. （ C） Various colors of tree leaves. （ D） Color changes of tree leaves. （ A） Because nature wants them to look beautiful. （ B） Because they are going to fall. （ C） Because there are
39、 fewer daylight hours in autumn. （ D） Because red and yellow colors are no longer hidden by the green. （ A） A assignment. （ B） A grade. （ C） A class. （ D） An examination. （ A） The election system in India. （ B） The festivals in India. （ C） The political system of India. （ D） The arts customs in Indi
40、a. （ A） Her paper due the next week. （ B） Her most recent exam grade. （ C） The material on the exam. （ D） Not being able to get lunch （ A） To the library. （ B） To the classroom. （ C） To the department store. （ D） To the canteen. Section B Directions: In this section, you will hear 3 short passages.
41、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） Ask for their names. （ B） Name babies after them. （ C） Put down their nam
42、es. （ D） Choose names for them. （ A） If the family tree is fairly limited. （ B） If the family tie is strong enough. （ C） If the name is commonly used. （ D） If nobody in the family complains. （ A） It will show the beauty of its own. （ B） It will develop more associations. （ C） It will lose the origin
43、al meaning. （ D） It will help form the babys personality. （ A） The Black Plague. （ B） Common Animal pests. （ C） Enemy of Humanity. （ D） Causes of World Hunger. （ A） They eat or spoil crops. （ B） They attack birds and animals. （ C） They destroy dams and buildings. （ D） They carry diseases. （ A） In In
44、dia. （ B） Throughout the world. （ C） In Europe, （ D） Both A and B. （ A） To save 3 dollars. （ B） To buy it at once. （ C） To ask 3 dollars from the parent. （ D） To save 5 dollars. （ A） Understanding the importance of money. （ B） Understanding the value of life. （ C） Understanding the complicated socie
45、ty. （ D） Buying cheap things. （ A） She holds that one dollar for each year of the age is far from enough. （ B） She believes that children should be given more than they need. （ C） She feels that difference doesnt matter. （ D） She thinks that age difference is not the whole thing. （ A） Give 5 dollars
46、 to children more than 15 years old. （ B） Allow a yearly increase as their children grow older. （ C） Teach their children how to make money and use it wisely. （ D） Refuse to give money to children. Section C Directions: In this section, you will hear a passage three times. When the passage is read f
47、or the first time, you should listen carefully for its general 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 informa
48、tion. For these blanks, you can either use the exact words you have just heard or write down the 36 You should not fear spiders because of their poison. Of all the spiders in North America, only one kind is very【 B1】 _and most would not bite even if they were【 B2】 _. They much prefer to run away or
49、to drop to the ground on a【 B3】 _of silk. Even so, when a spider runs directly toward a person, it gives the【 B4】 _that it is about to attack. Actually, it cannot see the person in its way. The spider is too【 B5】 _to see things at a distance. It only wants to go where it wouldnt be【 B6】 _. In the United States only one kind of spider is responsible for the frightening【 B7】 _of the rest. It is the Black Widow(黑寡妇 ). So called because the female, which is larger than the
