PART Ⅳ GRAMMAR AND VOCABULARY TEXT A Although numbers of animals in a given region may fluctuate from year to year, the fluctuations are often temporary and, over long periods, trivial. Scientists have advanced three theories of population control to account for this relative constancy.
The first theory attributes a relatively constant population to periodic climatic catastrophes that decimate populations with such frequency as to prevent them from exceeding some particular limit. In the case of small organisms with short life cycles, climatic changes need not be catastrophic: normal seasonal changes in photoperiod (daily amount of sunlight), for example, can govern population growth. This theory—the density independent view—asserts that climatic factors exert the same regulatory effect on population regardless of the number of individuals in a region.
A second theory argues that population growth is primarily density-dependent—that is, the rate of growth of a population in a region decreases as the number of animals increases. The mechanisms that manage regulation may vary. For example, as numbers increase, the food supply would probably diminish, which would increase mortality. In addition, as Lotka and Volterra have shown, predators can find prey more easily in high-density populations. Other regulators include physiological control mechanisms: for example, Christian and Davis have demonstrated how the crowding that results from a rise in numbers may bring about hormonal changes in the pituitary (垂体) and adrenal glands (肾上腺) that in turn may regulate population by lowering sexual activity and inhibiting sexual maturation. There is evidence that these effects may persist for three generations in the absence of the original provocation. One challenge for density-dependent theorists is to develop models that would allow the precise prediction of the effects of crowding.
A third theory, proposed by Wynne-Edwards and termed "epideictic", argues that organisms have evolved a "code" in the form of social or epideictic behavior displays, such as winter roosting aggregations or group vocalizing; such codes provide organisms with information on population size in a region so that they can, if necessary, exercise reproductive restraint. However, Wynne-Edwards' theory, linking animal social behavior and population control, has been challenged, with some justification, by several studies. TEXT E As citizens of advanced but vulnerable economies, we must either relentlessly increase the quality of our skills or see our standard of living erode. For the future, competition between nations will be increasingly based on technological skill. Oil and natural resources will still be important, but they no longer will determine a nation’s economic strength. This will now be a matter of the way people organize themselves and the nature and quality of their work. Japan and the "new Japans" of East Asia are demonstrating this point in ways that are becoming painfully obvious to the older industrial countries.
There is simply no way to rest on our past achievements. Today’s competition renders obsolete huge chunks of what we know and what forces us to innovate. For each individual, several careers will be customary, and continuing education and retraining will be inescapable. To attain this extraordinary level of education, government, business, schools, and even individuals will turn to technology for the answer.
In industry, processing the information and designing the changes necessary to keep up with the market has meant the growing use of computers. The schools are now following close behind. Already some colleges in the United States are requiring a computer for each student. It is estimated that 500,000 computers are already in use in American high schools and elementary schools. Although there is an abysmal lack of educational software, the number of computers in schools expands rapidly.
The computer is the Proteus of machines, as it takes on a thousand forms and serves a thousand functions. But its truly revolutionary character can be seen in its interactive potential. With advanced computers, learning can be individualized and serf-paced. Teachers can become more productive and the entire learning environment enriched.
It is striking how much current teaching is a product of pencil and paper technology. With the computer’s capacity for simulation and diverse kinds of feedback, all sorts of new possibilities open up for the redesign of curriculums. Seymour Papert, the inventor of the computer language LOGO, believes that concepts in physics and advanced mathematics can be taught in the early grades with the use of computers. On every-day level, word-processing significantly improves the capacity for written expression. In terms of drill and practice, self-paced computer-assisted instruction enables the student to advance rapidly-without being limited by the conflicting needs of the entire class. In short, once we learn to use this new brain outside the brain, education will never be the same.
Industry, faced with the pressures of a rapidly shifting market, is already designing new methods to retrain its workers. In the United States, a technological university has been set up to teach engineering courses by satellite. And the advances in telecommunications and computational power will dramatically expand the opportunities for national and international efforts in education and training.
Without romanticizing the machine, it is clear that computers uniquely change the potential for equipping today’s citizens for unprecedented tasks of the future. Particularly in Europe and the United Sates, innovation will be the basis for continued prosperity. New competitors are emerging to challenge the old economic arrangements. How successfully we respond will depend on how much we invest in people and how wisely we employ the learning tools of the new technology. SECTION A COMPOSITION1.
Mobile phone nowadays creates a new way of life, but meanwhile it brings about embarrassing situations and mobile phone etiquette becomes a real problem. Analyze the reasons and some suggestions are required to be provided. Write on ANSWER SHEET TWO a composition of about 200 words on the following topic:
Mobile Phone Etiquette You are to write in three parts.
In the first part, state specifically what your opinion is.
In the second part, provide one or two reasons to support your opinion.
In the last part, bring what you have written to a natural conclusion or make a summary.
Marks will be awarded for content, organization, grammar and appropriateness. Failure to follow the instructions may result in a loss of marks.
[参考范文]
Mobile Phone Etiquette
The mobile phone has created a new way of life. It gives us the opportunity to reach people whenever and wherever we like. But when mobile phones become as commonplace as wrist- watches, it seems they are also creating embarrassing situations.
Sometimes such occasions come without notice. We let our phones ring in restaurants, theatres, classrooms, or business meetings. People discuss their personal issues loudly over their phones while strangers are around. People spend all their time in the presence of friends paying more attention to those at the other end of their mobile phones. Now mobile phone etiquette is a big problem.
Here are some tips for being a good mobile phone user. Firstly, remember to check your phone is off at activities. Secondly, respect the people around you when making calls in public. Thirdly, don't answer your phone while talking with another person unless that phone call is more important than the person you are with. Bearing these rules in our minds, we will be a responsible and considerate user. The disharmonious voice will vanish with the rising of the awareness that every one of us shall not be so careless and indifferent to things around us. Live, and let live. Only in this way will a harmonious society full of love and light never be a dream!
[解析]
文章的中心思想是呼吁大家要“做一名文明的手机用户”。首先应该提出论点,随着手机用户的增多,问题出现了,做一名文明手机用户的重要性凸现;接着需要阐述这种现象、分析问题的影响及其产生的原因;最后进行总结,提出解决问题的办法,指出只要我们每个人多为别人考虑一下,就会成为一个文明的手机用户。注意分析问题要深入,最后呼吁要辞情恳切。
SECTION B NOTE-WRITING1. Jesse, one of your foreign friends, intends to pursue a higher education in China. She iikes Chinese culture very much and asks you for general information in this regard. Write a note, recommending to her the ideal university she might choose.
Marks will be awarded for content, organization, language and appropriateness.
Dear Jesse,
I'm glad to hear that you intend to pursue your higher education in China. Almost every university in China has a department of Chinese. If you are much interested in Chinese culture, I suggest you apply for such a program at Beijing Language and Culture University, for it has been regarded as an authority in teaching foreign students Chinese and its culture. I wish you success and hope to see you in China.
Sincerely Yours