2019 年 12 月大学英语六级考试真题（第 3 套）

The persistent haze over many of our cities is a reminder of the polluted air that we breathe. Over 80% of the world's urban population is breathing air that fails to meet World Health Organisation sidelines, and an estimated 4.5 million people died __26__ from outdoor air pollution in 2015. Globally, urban populations are expected to double in the next 40 years, and an extra 2 billion people will need new places to live, as well as services and ways to move around their cities. What is more important, the decisions that we make now about the design of our cities will __27__ the everyday lives and health of the coming generations. So what would a smog-free, or at least low-pollution, city be like? Traffic has become __28__ with air pollution, and many countries intend to ban the sale of petrol and diesel cars in the next two decades. But simply __29__ to electric cars will not mean pollution-free cities. The level of emissions they cause will depend on how the electricity to run them is __30__, while brakes, tyres and roads all create tiny airborne __31__ as they wear out. Across the developed world, car use is in decline as more people move to city centres, while young people especially are __32__ for other means of travel. Researchers are already asking if motor vehicle use has reached its __33__ and will decline, but transport planners have yet to catch up with this __34__, instead of laying new roads to tackle traffic jams. As users of London's orbital M25 motorway will know, new roads rapidly fill with more traffic. In the US, studies have shown that doubling the size a road can __35__ double the traffic, taking us back to the starting point.

Schools are not just a microcosm of society; they mediate it too. The best seek to alleviate the external pressures on their pupils while equipping them better to understand and handle the world outside-at once sheltering them and broadening their horizons. This is ambitious in any circumstances, and in a divided and unequal society the two ideals can clash outright. Trips that many adults would consider the adventure of a lifetime-treks in Borneo, a sports tour to Barbadoes - appear to have become almost routine at some state schools. Parents are being asked for thousands of pounds. Though schools cannot profit from these trips, the companies that arrange them do. Meanwhile, pupils arrive at school hungry because their families can't afford breakfast. The Child Poverty Action Group says nine out of 30 in every classroom fall below the poverty line. The discrepancy is startlingly apparent. Introducing a fundraising requirement for students does not help, as better-off children can tap up richer aunts and neighbors. Probing the rock pools of a local beach or practicing French on a language exchange can fire children's passions, boost their skills and open their eyes to life's possibilities. Educational outings help bright but disadvantaged students to get better scores in A-level tests. In this globalized age, there is a good case for international travel, and some parents say they can manage the cost of a school trip abroad more easily than a family holiday. Even in the face of immense and mounting financial pressures, some schools have shown remarkable determination and ingenuity in ensuring that all their pupils are able to take up opportunities that may be truly life-changing. They should be applauded. Methods such as whole-school fundraising, with the proceeds pooled, can help to extend opportunities and fuel community spirit. But ￡3,000 trips cannot be justified when the average income for families with children is just over ￡30,000. Such initiatives close doors for many pupils. Some parents pull their children out of school because of expensive field trips. Even parents who can see that a trip is little more than a party or celebration may well feel guilt that their child is left behind. The Department for Education's guidance says schools can charge only for board and lodging if the trip is part of the syllabus, and that students receiving government aid are exempt from these costs. However, many schools seem to ignore the advice, and it does not cover the kind of glamorous, exotic trips, which are becoming increasingly common. Schools cannot be expected to bring together communities single-handed. But the least we should expect is that they do not foster divisions and exclude those who are already disadvantaged.

Rising temperatures and overfishing in the pristine (未受污染的) waters around the Antarctic could see King penguin populations pushed to the brink of extinction by the end of the century, according to a new study. The study's report states that as global warming transforms the environment in the world's last great wilderness, 70 percent of king penguins could either disappear or be forced to find new breeding grounds. Co-author Céline Le Bohec, from the University of Strasbourg in France, warned: "If there're no actions aimed at halting or controlling global warming, and the pace of the current human-induced changes such as climate change and overfishing stays the same, the species may soon disappear." The findings come amid growing concern over the future of the Antarctic. Earlier this month a separate study found that a combination of climate change and industrial fishing is threatening the krill (磷虾) population in Antarctic waters, with a potentially disastrous impact on whales, seals and penguins. But today's report is the starkest warning yet of the potentially devastating impact of climate change and human exploitation on the Antarctic's delicate ecosystems. Le Bohec said, "Unless current greenhouse gas emissions drop, 70 percent of king penguins—1.1 million breeding pairs—will be forced to relocate their breeding grounds, or face extinction by 2100." King penguins are the second-largest type of penguin and only breed on specific isolated islands in the Southern Ocean where there is no ice cover and easy access to the sea. As the ocean warms, a body of water called the Antarctic Polar Front—an upward movement of nutrient-rich sea that supports a huge abundance of marine life—is being pushed further south. This means that king penguins, which feed on fish and krill in this body of water, have to travel further to their feeding grounds, leaving their hungry chicks for longer. And as this distance between their breeding grounds and their food grows, entire colonies could be wiped out. Le Bohec said, "The plight of the king penguin should serve as a warning about the future of the entire marine environment in the Antarctic. Penguins, like other seabirds and marine mammals, occupy higher levels in the food chain and they are what we call bio-indicators of their ecosystems." Penguins are sensitive indicators of changes in marine ecosystems. As such, they are key species for understanding and predicting impacts of global change on Antarctic and sub-Antarctic marine ecosystems. The report found that although some king penguins may be able to relocate to new breeding grounds closer to their retreating food source, suitable new habitats would be scarce. Only a handful of islands in the Southern Ocean are suitable for sustaining large breeding colonies.