well as our lifetime‘s knowledge. But is there a point where it reaches capacity?
The answer is no, because brains are more sophisticated than that. Instead of just crowding in, old information is sometimes pushed out of the brain for new memories to form.
Previous behavioural studies have shown that learning new information can lead to forgetting. But in a new study, researchers demonstrated for the first time how this effect occurs in the brain.
In daily life, forgetting actually has clear advantages. Imagine, for instance, that you lost your bank card. The new card you receive will come with a new personal identificatipn number (PIN). Each time you remember the new PIN, you gradually forget the old one. This process improves access to relevant information, without old memories interfering.
And most of us may sometimes feel the frustration of having old memories interfere with new, relevant memories. Consider trying to remember where you parked your car in the same car park you were at a week earlier. This type of memory (where you are trying to remember new, but similar information) is particularly vulnerable to interference.
When we acquire new information, the brain automatically tries to incorporate (合并)it within existing information by forming associations. And when we retrieve (检索)information, both the desired and associated but irrelevant information is recalled.,
The majority of previous research has focused on how we learn and remember new information. But current studies are beginning to place greater emphasis on the conditions under which we forget, as its importance begins to be more appreciated.
A very small number of people are able to remember almost every detail of their life. While it may sound like an advantage to many, people with this rare condition often find their unusual ability burdensome.
In a sense, forgetting is our brain‘s way of sorting memories, so the most relevant memories are ready for retrieval. Normal forgetting may even be a safety mechanism to ensure our brain doesn‘t become too full.
注意：此部分试题请在答题卡2上作答。
51. What have past behavioural studies found about our brain? A) Its capacity actually knows no limits. B) It grows sophisticated with practice.
C) It keeps our most precious memories until life‘s end.
D) New information learned pushes old information out.
52. What is the benefit of forgetting? A) It frees us from painful memories.
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B) It helps slow down our aging process. C) It facilitates our access to relevant information.
D) It prevents old information from forming associations.
53. What is the emphasis of current studies of memory? A) When people tend to forget. B) What contributes to forgetting.
C) How new technology hinders memory capacity.
D) Why learning and forgetting arc complementary.
54. What do people find about their rare ability to remember every detail of their life? A) It adds to the burden of their memory. B) It makes their life more complicated. C) It contributes to their success in life.
D) It constitutes a rare object of envy.
55. What does the passage say about forgetting? A) It can enlarge our brain capacity. B) It helps get rid of negative memories. C) It is a way of organising our memories. D) It should not cause any alarm in any way.
Part IV Translation (30 minutes)
Directions: For this part, you are allowed 30 minutes to translate a passage from Chinese into English. You should write your answer on Answer Sheet 2.
长江是亚洲最长、世界上第三长的河流。长江流经多种不同的生态系统，是诸多濒危物种的栖息地，灌溉了中国五分之一的土地。长江流域(river basin )居住着三分之一的人口。长江在中国历史、文化和经济上起着很大的作用。长江三角洲(delta)产出多达20%的中国国民生产总值。几千年来，长江一直被用于供水、运输和工业生产。长江上还坐落着世界最大的水电站。
注意：此部分试题请在答题卡2上作答。
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参考答案
1-5 CACBD 6-10 DBCAB 11-15 DBADC 16-20 ADBAB 21-25 DACCB 26-30 JCGMA 31-35 FIKHB 36-40 GDLBF 41-45 CHAKE 46-50 BCCDB 51-55 DCBAC
翻译第二套答案：
长江是亚洲最长、世界上第三长的河流。长江流经多种不同的生态系统，是诸多濒危物种的栖息地，灌溉了中国五分之一的土地。长江流域居住着中国三分之一的人口。长江在中国历史、文化和经济上起着很大的作用。长江三角洲产出多达20%的中国国民生产总值。几千年来，长江一直被用于供水，运输和工业生产。长江上还坐落着世界最大的水电站。
TheYangtze River is the longest river in Asia and also the third longest riveraround the world. Yangtze River which flows through a variety of differentecosystems, is the habitat of many endangered species, irrigating one fifth ofthe land in China. The Yangtze River Basin is home to one third of Chinesepopulation, which plays a significant role on Chinese history, culture andeconomy. The Yangtze River Delta produces up to twenty percent of China's GrossNational Product. For thousands of years, the Yangtze River has been takenadvantages of water supply, transportation and industrial production. Besides,the world‘s largest hydro-electric power station stands on the Yangtze River.
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2017年6月大学英语四级真题及答案
(第三套)
Part I Writing (30 minutes)
(请于正式开考后半小时内完成该部分，之后将进行听力考试)
Directions:For this part, you are allowed 30 minutes to write an advertisement on your campus website to sell some of the course books you used at college. Your advertisement may include a brief description of their content,their condition ,their price and your contact information. You should write at least 120 words but no more than 180 words.
Part II Listening Comprehension (25 minutes) 同第二套
Part ⅢReading Comprehension (40 minutes)
Section A
Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices, Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once.
Questions 26 to 35 are based on the following passage.
As if you needed another reason to hate the gym, it now turns out that exercise can exhaust not only your muscles, but also your eyes. Fear not, however, for coffee can stimulate them again. During(26)_______ exercise, our muscles tire as they run out of fuel and build up waste products. Muscleperformance can also be affected by a (27)_______ called \fatigue,‖ in which an imbalance inthe body‘s chemical messengers prevents the central nervous system from directing muscle movements（28)_______. It was not known, however, whether central fatigue might also affect motor systems notdirectly (29)
_______ in the exercise itself, such as those that move the eyes. To
find out, researchersgave 11 volunteer cyclists a carbohydrate (碳水化合物的）(30)_______ either with a moderate doseof caffeine (咖啡因)，which is known to stimulate the central nervous system, or as a placebo (安慰剂） without, during 3 hours of (31)_______ . After exercising, the scientists tested the cyclists with eyetracking cameras to see how well their brains could still (32)_______ their
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