Navigation computers, now sold by most car-makers, cost $2,000 and up. No surprise, then, that they are most often found in luxury cars, like Lexus, BMW and Audi. But it is a developing technology—meaning prices should eventually drop—and the market does seem to be growing.
　　Even at current prices, a navigation computer is impressive. It can guide you from point to point in most major cities with precise turn-by-turn directions—spoken by a clear human-sounding voice, and written on a screen in front of the driver.
　　The computer works with an antenna (天线) that takes signals from no fewer than three of the 24 global positioning system (GPS) satellites. By measuring the time required for a signal to travel between the satellites and the antenna, the car’s location can be pinned down within 100 meters.
　　The satellite signals, along with inputs on speed from a wheel-speed sensor and direction from a meter, determine the car’s position even as it moves. This information is combined with a map database. Streets, landmarks and points of interest are included.
　　Most systems are basically identical. The differences come in hardware—the way the computer accepts the driver’s request for directions and the way it presents the driving instructions. On most systems, a driver enters a desired address, motorway junction or point of interest via a touch screen or disc. But the Lexus screen goes a step further: you can point to any spot on the map screen and get directions to it.
　　BMW’s system offers a set of cross hairs (瞄准器上的十字纹) that can be moved across the map (you have several choices of map scale) to pick a point you’d like to get to. Audi’s screen can be switched to TV reception.
　　Even the voices that recite the directions can differ, with better systems like BMW’s and Lexus’s having a wider vocabulary. The instructions are available in French, German, Spanish, Dutch and Italian, as well as English. The driver can also choose parameters for determining the route: fastest, shortest or no freeways (高速公路), for example.

　　“The world's environment is surprisingly healthy. Discuss.” If that were an examination topic, most students would tear it apart, offering a long list of complaints: from local smog (烟雾) to global climate change, from the felling (砍伐) of forests to the extinction of species. The list would largely be accurate, the concern legitimate. Yet the students who should be given the highest marks would actually be those who agreed with the statement. The surprise is how good things are, not how bad.
　　After all, the world's population has more than tripled during this century, and world output has risen hugely, so you would expect the earth itself to have been affected. Indeed, if people lived, consumed and produced things in the same way as they did in 1900 (or 1950, or indeed 1980), the world by now would be a pretty disgusting place: smelly, dirty, toxic and dangerous.
　　But they don't. The reasons why they don't, and why the environment has not been mined, have to do with prices, technological innovation, social change and government regulation in response to popular pressure. That is why, today's environmental problems in the poor countries ought, in principle, to be solvable.
　　Raw materials have not run out, and show no sign of doing so. Logically, one day they must: the planet is a finite place. Yet it is also very big, and man is very ingenious. What has happened is that every time a material seems to be running short, the price has risen and, in response, people have looked for new sources of supply, tried to find ways to use less of the material, or looked for a new substitute. For this reason prices for energy and for minerals have fallen in real terms during the century. The same is true for food. Prices fluctuate, in response to harvests, natural disasters and political instability; and when they rise, it takes some time before new sources of supply become available. But they always do, assisted by new farming and crop technology. The long term trend has been downwards.
　　It is where prices and markets do not operate properly that this benign (良性的) trend begins to stumble, and the genuine problems arise. Markets cannot always keep the environment healthy. If no one owns the resource concerned, no one has an interest in conserving it or fostering it: fish is the best example of this.

　　About the time that schools and others quite reasonably became interested in seeing to it that all children, whatever their background, were fairly treated, intelligence testing became unpopular.
　　Some thought it was unfair to minority children. Through the past few decades such testing has gone out of fashion and many communities have indeed forbidden it.
　　However, paradoxically, just recently a group of black parents filed a lawsuit (诉讼) in California claiming that the state's ban on IQ testing discriminates against their children by denying them the opportunity to take the test. (They believed, correctly, that IQ tests are a valid method of evaluating children for special education classes.) The judge, therefore, reversed, at least partially, his original decision.
　　And so the argument goes on and on. Does it benefit or harm children from minority groups to have their intelligence tested? We have always been on the side of permitting, even facilitating, such testing. If a child of any color or group is doing poorly in school it seems to us very important to know whether it is because he or she is of low intelligence, or whether some other factor is the cause.
　　What school and family can do to improve poor performance is influenced by its cause. It is not discriminative to evaluate either a child's physical condition or his intellectual level.
　　Unfortunately, intellectual level seems to be a sensitive subject, and what the law allows us to do varies from time to time. The same fluctuation back and forth occurs in areas other than intelligence. Thirty years or so ago, for instance, white families were encouraged to adopt black children. It was considered discriminative not to do so.
　　And then the style changed and this cross-racial adopting became generally unpopular, and social agencies felt that black children should go to black families only. It is hard to say what are the best procedures. But surely good will on the part of all of us is needed.
　　As to intelligence, in our opinion, the more we know about any child's intellectual level, the better for the child in question.

　　Not too many decades ago it seemed “obvious” both to the general public and to sociologists that modern society has changed people's natural relations, loosened their responsibilities to kin (亲戚) and neighbors, and substituted in their place superficial relationships with passing acquaintances. However, in recent years a growing body of research has revealed that the “obvious” is not true. It seems that if you are a city resident, you typically know a smaller proportion of your neighbors than you do if you are a resident of a smaller community. But, for the most part, this fact has few significant consequences. It does not necessarily follow that if you know few of your neighbors you will know no one else.
　　Even in very large cities, people maintain close social ties within small, private social worlds. Indeed, the number and quality of meaningful relationships do not differ between more and less urban people. Small-town residents are more involved with kin than are big-city residents. Yet city dwellers compensate by developing friendships with people who share similar interests and activities. Urbanism may produce a different style of life, but the quality of life does not differ between town and city. Nor are residents of large communities any likelier to display psychological symptoms of stress or alienation, a feeling of not belonging, than are residents of smaller communities. However, city dwellers do worry more about crime, and this leads them to a distrust of strangers.
　　These findings do not imply that urbanism makes little or no difference. If neighbors are strangers to one another, they are less likely to sweep the sidewalk of an elderly couple living next door or keep an eye out for young trouble makers. Moreover, as Wirth suggested, there may be a link between a community's population size and its social heterogeneity (多样性). For instance, sociologists have found much evidence that the size of a community is associated with bad behavior including gambling, drugs, etc. Large-city urbanites are also more likely than their small-town counterparts to have a cosmopolitan (见多识广者的) outlook, to display less responsibility to traditional kinship roles, to vote for leftist political candidates, and to be tolerant of nontraditional religious groups, unpopular political groups, and so-called undesirables. Everything considered, heterogeneity and unusual behavior seem to be outcomes of large population size.

While a full understanding of what causes the disease may be several years away, ______ leading to a successful treatment could come much sooner.

All the guests were invited to attend the wedding ______ and had a very good time.

    Sporting activities are essentially modified forms of hunting behavior. Viewing biologically, the modern (S1) footballer is revealed as a member of a disguised hunting pack. His killing weapon has turned into a harmless football and his prey into a goal-mouth. If his aim is inaccurate and he (S2)scores a goal, enjoys the hunter’s triumph of killing his prey. (S3)
    To understand how this transformation has taken place we must briefly look up at our ancient ancestors. They spent over a (S4) million year evolving as co-operative hunters. Their very survival (S5) depended on success in the hunting-field. Under this pressure their whole way of life, even if their bodies, became radically (S6) changed. They became chasers, runners, jumpers, aimers, throwers and prey-killers. They co-operate as skillful male-group (S7) attackers.
    Then, about ten thousand years ago, when this immensely (S8) long formative period of hunting for food, they became farmers.
    Their improved intelligence, so vital to their old hunting life, were put to a new use-that of penning （把 ...... 关在圈中）, (S9) controlling and domesticating their prey. The food was there on the farms, awaiting their needs. The risks and uncertainties of farming were no longer essential for survival. (S10)

This part is to test your ability to do practical writing．You are required to write a letter according to the following information given in Chinese．You should write no less than 60 words ort the Composition/Translation Sheet．
假设你是李明，请你就本校食堂的状况给校长写一封信，内容应涉及食堂的饭菜质量、价格、环境、服务等，可以是表扬，可以是批评建议，也可以兼而有之。