A classic series of experiments to determine the effects of overpopulation on communities of rats was conducted by a psychologist, John Calhoun. In each experiment, an equal number of male and female adult rats were placed in an enclosure. The rat populations were allowed to increase. Calhoun knew from experience approximately how many rats could live in the enclosures without experiencing stress due to over crowding. He allowed the population to increase to approximately twice this number. Then he stabilized the population by removing offspring that were not dependent on their mothers. At the end of the experiments, Calhoun was able to conclude that overcrowding causes a break down in the normal social relationships among rats, a kind of social disease. The rats in the experiments did not follow the same patterns of behavior as rats would in a community without overcrowding. The females in the rat population were the most seriously affected by the high population density. For example, mothers sometimes abandoned their pups, and, without their mothers’ care, the pups died. The experiments verified that in overpopulated communities, mother rats do not-behave normally. Their behavior may be considered diseased, pathological. The dominant males in the rat population were the least affected by overpopulation. Each of these strong males claimed an area of the enclosure as his own. Therefore, these individuals did not experience the overcrowding in the same way as the other rats did. However, dominant males did behave pathologically at times. Their antisocial behavior consisted of attacks on weaker male, female, and immature rats. This deviant behaviour showed that even though the dominant males had enough living space, they too were affected by the general overcrowding. Nondominant males in the experimental rat communities also exhibited deviant social behavior, Some withdrew completely, avoiding contact with other rats. Other nondominant males were hyperactive, chasing other rats and fighting each other. The behaviour of the rat population has parallels in human behavior. People in densely populated areas exhibit deviant behavior similar to that of the rats in Calhoun’s experiments. In large urban areas, such as New York City, London, and Cairo, there are abandoned children. There are cruel, powerful individuals, both men and women. There are also people who withdraw and people who become hyperactive. Is the principal cause of these disorders. overpopulation Calhoun’ s experiments suggest that it might be. In any case, social scientists and city planners have been influenced by the results of this series of experiments.Calhoun stabilized the rat population（） A. when it was double the number that could live in the enclosure without stressB. by removing young ratsC. so that there was a constant number of adult rats in the enclosure D.All of the above are correct

An entrepreneur who identifies too strongly with his business may equate its fortunes ___ his own worth.

Use the words from the box to complete the following sentences and change forms when-|||-necessary.The words are the same as Task 5 while the sentences create new contexts.-|||-achieve confirm dedicate dignity yield-|||-ambitious contribute embrace wither reconcile-|||-1.I'd like to thank all who contributed their time and effort.-|||-2.Many elderly people are unwilling to embrace new technologies.-|||-3.After years of struggle,the nation finally achieved independence.-|||-4.How can you reconcile wearing a fur coat with your love of animals?-|||-5.We plan to dedicate the day to visiting several art galleries in the city.-|||-6.Due to the lack of of rain,the grass in the fields began to wither.-|||-7.We should strive to create a society in which the dignity of all people is recognized.-|||-8.The government has announced a(n)ambitious plan to modernize the railway network.-|||-9.Our army refused to yield even as the occupying forces surround the city.-|||-10.Olivia confirmed that she would come to the party this weekend.

(2.0分)Laozi is a book on the_and_ ,which has played an important role in Chinese culture . A nature and human B parents and children C water and life D way and virtue

40. Jack and I were riding in the back of a long black car, insulated from the heat and dust as it followed an empty road through a ______ desert landscape.A. radiantB. robustC. boundD. barren

根据首字母提示填出完整单词。As we know, the westerners are particular about clothes wearing. On different o______ , they wear different clothes.

The ______ noise from the construction site made it impossible to concentrate.A. temporaryB. perpetualC. occasionalD. trivial

28. ________ an English-Chinese dictionary. A. The students each haveB. The students each hasC. Each the students hasD. Each of the students have

CET-4真题: 阅读 202106-2Section C-- Passage TwoQuestions 51 to 55 are based on the following passage.Success was once defined as being able to stay at a company for a long time and move up the corporate ladder. The goal was to reach the top, accumulate wealth and retire to a life of ease. My father is a successful senior executive. In 35 years, he worked for only three companies.When I started my career, things were already different. If you weren't changing companies every three or four years, you simply weren't getting ahead in your career. But back then, if you were a consultant or freelancer [自由职业者], people would wonder what was wrong with you. They would assume you had problems getting a job.Today, consulting or freelancing for five businesses at the same time is a badge of honor. It shows how valuable an individual is. Many companies now look to these “ultimate professionals" to solve problems their full-time teams can't. Or they save money by hiring top-tier [顶尖的] experts only for particular projects.Working at home or in cafes, starting businesses of their own, and even launching business ventures that eventually may fail, all indicate " initiative", " creativity", and " adaptability", which are desirable qualities in today's workplace. Most important, there is a growing recognition that people who balance work and play, and who work at what they are passionate about, are more focused and productive, delivering greater value to their clients.Who are these people? They are artists, writers, programmers, providers of office services and career advice. What's needed now is a marketplace platform specifically designed to bring freelancers and clients together. Such platforms then become a place to feature the most experienced, professional, and creative talent. This is where they conduct business, where a sense of community reinforces the culture and values of the gig economy [零工经济], and where success is rewarded with good reviews that encourage more business.Slowly but surely, these platforms create a bridge between traditional enterprises and this emerging economy. Perhaps more important, as the global economy continues to be disrupted by technology and other massive change, the gig economy will itself become an engine of economic and social transformation. [368 words](1) (单选题)What does the author use the example of his father to illustrate?A.How long people took to reach the top of their career.B.How people accumulated wealth in his father's time.C.How people viewed success in his father's time.D.How long people usually stayed in a company.(2) (单选题)Why did people often change jobs when the author started his career?A.It was considered a fashion at that time.B.It was a way to advance in their career.C.It was a response to the changing job market.D.It was difficult to keep a job for long.(3) (单选题)What does the author say about people now working for several businesses at the same time?A.They are often regarded as most treasured talents.B.They are able to bring their potential into full play.C.They have control over their life and work schedules.D.They feel proud of being outstanding problem solver.(4) (单选题)What have businesses come to recognize now?A.Who is capable of solving problems with ease.B.How people can be more focused and productive.C.What kind of people can contribute more to them.D.Why some people are more passionate about work.(5) (单选题)What does the author say about the gig economy?A.It may force companies to reform their business practice.B.It may soon replace the traditional economic model.C.It will drive technological progress on a global scale.D.It will bring about radical economic and social changes.