2019年12月大学英语六级真题试卷（二）

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 guidelines, and an estimated 4.5 million people died【C1】______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【C2】______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【C3】___with air pollution, and many countries intend to ban the sale of new petrol and diesel cars in the next two decades. But simply【C4】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【C5】, while brakes, tyres and roads all create tiny airborne【C6】___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【C7】___for other means of travel. Researchers are already asking if motor vehicle use has reached its【C8】and will decline, but transport planners have yet to catch up with this【C9】, 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 of a road can【C10】___double the traffic, taking us back to the starting point.

A) alternate F) merged K) prematurely

B) crown G) miniatures L) simply

C) determine H) opting M) switching

D) generated I) particles N) synonymous

E) locating J) peak O) trend

How much protein do you really need?

A) The marketing is tempting: Get stronger muscles and healthier bodies with minimal effort by adding protein powder to your morning shake or juice drink. Or grab a protein bar at lunch or for a quick snack. Today, you can find protein supplements everywhere—online or at the pharmacy, grocery store or health food store. They come in powders, pills and bars. With more than $ 12 billion in sales this year, the industry is booming and, according to the market research company, Grand View Research, is on track to sell billions more by 2025. But do we really need all this supplemental protein? It depends. There are pros, cons and some other things to consider.

B) For starters, protein is critical for every cell in our body. It helps build nails, hair, bones and muscles. It can also help you feel fuller longer than eating foods without protein. And, unlike nutrients that are found only in a few foods, protein is present in all foods. “The typical American diet is a lot higher in protein than a lot of us think,” says registered dietitian Angela Pipitone. “It’s in foods many of us expect, such as beef, chicken and other types of meat and dairy. But it’s also in foods that may not come immediately to mind like vegetables, fruit, beans and grains.”

C) The U. S. government’s recommended daily allowance (RDA) for the average adult is 50 to 60 grams of protein a day. This may sound like a lot, but Pipitone says: “We get bits of protein here and there and that really adds up throughout the day.” Take, for example, breakfast. If you eat two eggs topped with a little bit of cheese and an orange on the side, you already have 22 grams of protein. Each egg gives you 7 grams, the cheese gives you about 6 grams and the orange—about 2 grams. Add a lunch of chicken, rice and broccoli (西兰花), and you are already over the recommended 50 grams. “You can get enough protein and meet the RDA before you even get to dinner,” says Pipitone.

D) So if it’s so easy to get your protein in food, why add more in the form of powders, snack bars or a boost at your local juice bar? No need to, says Pipitone, because, in fact, most of us already get enough protein in our diet. “Whole foods are always the best option rather than adding supplements,” she says, noting the FDA does not regulate supplements as rigorously as foods or drugs. So there could be less protein, more sugar and some additives you wouldn’t expect, such as caffeine (咖啡因).

E) If you are considering a supplement, read the list of ingredients, she says, although this is not always reliable. “I’ve seen very expensive protein supplements that claim to be high quality but they might not really be beneficial for the average healthy adult,” she says. “It could just be a waste of money. “

F) But there are certain situations that do warrant extra protein. “Anytime you’re repairing or building muscle,” Pipitone says, such as if you’re an extreme endurance athlete, training for a marathon, or you’re a body builder. If you’re moderately exercising for 150 minutes a week, as the Centers for Disease Control and Prevention recommends, or less than that, you’re probably not an extreme athlete. Extreme athletes expend lots of energy breaking down and repairing and building muscles. Protein can give them the edge they need to speed that process.

G) Vegans can benefit from protein supplements since they do not eat animal-based protein sources like meat, dairy or eggs. And, for someone always on-the-go who may not have time for a meal, a protein snack bar can be a good option for occasional meal replacement. Also, individuals recovering from surgery or an injury can also benefit from extra protein. So, too, can older people. At around age 60, “muscles really start to break down,” says Kathryn Starr, an aging researcher, “and because of that, the protein needs of an older adult actually increase.”

H) In fact, along with her colleague Connie Bales, Starr recently conducted a small study that found that adding extra protein foods to the diet of obese older individuals who were trying to lose weight strengthened their muscles. Participants in the study were separated into two groups—one group was asked to eat 30 grams of protein per meal in the form of whole foods. That meant they were eating 90 grams of protein a day. The other group—the control group—was put on a typical low-calorie diet with about 50 to 60 grams of protein a day. After six months, researchers found the high protein group had significantly improved their muscle function—almost twice as much as the control group. “They were able to walk faster, had improved balance, and were also able to get up out of a chair faster than the control group,” Starr says. All 67 participants were over 60 years of age, and both groups lost about the same amount of weight.

I) Starr is now looking into whether high-protein diets also improve the quality of the muscle itself in seniors. She’s using CT scans to measure muscle size and fat, and comparing seniors on a high-protein diet with those on regular diets. She says her findings should be available in a couple of months.

J) In the meantime, 70-year-old Corliss Keith, who was in the high protein group in Starr’s latest study, says she feels a big difference. “I feel excellent,” she says. “I feel like I have a different body, I have more energy, I’m stronger.” She says she is able to take Zumba exercise classes three times a week, work out on the treadmill (跑步机), and take long, brisk walks. Keith also lost more than 15 pounds. “I’m a fashionable person, so now I’m back in my 3-inch heels,” she says.

K) As people age, Starr says muscle strength is key to helping them stay strong and continue living on their own in their own home. “I feel very much alive now,” says Keith. “I feel like I could stay by myself until I’m 100.”

L) But can people overdo protein? Pipitone says you do have to be careful. Other researchers say too much protein can cause cramps (痉挛), headaches, and fatigue. Dehydration (脱水) is also a risk when you eat too much protein. Pipitone says if you increase protein, you also have to increase your fluid intake. “I always tell people to make sure they’re drinking enough fluids,” which for the average person is 60 to 70 ounces a day, which translates into eight 8-ounce glasses of water or liquid per day.

M) There have been some indications that extra protein makes the kidneys work harder, which could be problematic for individuals with a history of kidney disease and for them, the supplements may increase the risk of kidney stones, she says.

N) Bottom line, if you think you need more protein in your diet, consider these questions: Are you an extreme athlete; are you recovering from injury or surgery; or are you 60 years or older? If so, adding high protein foods like eggs and meat products to your diet can be beneficial. And, if you’re not sure, it is always a good idea to check with your primary care provider.

Last year, a child was born at a hospital in the UK with her heart outside her body. Few babies survive this rare condition, and those who do must endure numerous operations and are likely to have complex needs. When her mother was interviewed, three weeks after her daughter’s birth, she was asked if she was prepared for what might be a daunting (令人生畏的) task caring for her. She answered without hesitation that, as far as she was concerned, this would be a “privilege”.

Rarely has there been a better example of the power of attitude, one of our most powerful psychological tools. Our attitudes allow us to turn mistakes into opportunities, and loss into the chance for new beginnings. An attitude is a settled way of thinking, feeling and/or behaving towards particular objects, people, events or ideologies. We use our attitudes to filter, interpret and react to the world around us. You weren’t born with attitudes; rather they are all learned, and this happens in a number of ways.

The most powerful influences occur during early childhood and include both what happened to you directly, and what those around you did and said in your presence. As you acquire a distinctive identity, your attitudes are further refined by the behavior of those with whom you identify—your family, those of your gender and culture, and the people you admire, even though you may not know them personally. Friendships and other important relationships become increasingly important, particularly during adolescence. About that same time and throughout adulthood, the information you receive, especially when ideas are repeated in association with goals and achievements you find attractive, also refines your attitudes.

Many people assume that our attitudes are internally consistent, that is, the way you think and feel about someone or something predicts your behavior towards them. However, many studies have found that feelings and thoughts don’t necessarily predict behavior. In general, your attitudes will be internally consistent only when the behavior is easy, and when those around you hold similar beliefs. That’s why, for example, many say they believe in the benefits of recycling or exercise, but don’t behave in line with their views, because it takes awareness, effort and courage to go beyond merely stating that you believe something is a good idea.

One of the most effective ways to change an attitude is to start behaving as if you already feel and think the way you’d prefer to. Take some time to reflect on your attitudes, to think about what you believe and why. Is there anything you consider a burden rather than a privilege? If so, start behaving—right now—as if the latter is the case.

Industrial fishing for krill (磷虾) in the unspoilt waters around Antarctica is threatening the future of one of the world’s last great wildernesses, according to a new report.

The study by Greenpeace analysed the movements of krill fishing vessels in the region and found they were increasingly operating “in the immediate vicinity of penguin colonies and whale-feeding grounds”. It also highlights incidents of fishing boats being involved in groundings, oil spills and accidents, which posed a serious threat to the Antarctic ecosystem.

The report, published on Tuesday, comes amid growing concern about the impact of fishing and climate change on the Antarctic. A global campaign has been launched to create a network of ocean sanctuaries to protect the seas in the region and Greenpeace is calling for an immediate halt to fishing in areas being considered for sanctuary status.

Frida Bengtsson from Greenpeace’s Protect the Antarctic campaign said: “If the krill industry wants to show it’s a responsible player, then it should be voluntarily getting out of any area which is being proposed as an ocean sanctuary, and should instead be backing the protection of these huge tracts of the Antarctic.”

A global campaign has been launched to turn a huge tract of Antarctic seas into ocean sanctuaries, protecting wildlife and banning not just krill fishing, but all fishing. One was created in the Ross Sea in 2016, another reserve is being proposed in a vast area of the Weddell Sea, and a third sanctuary is under consideration in the area west of the Antarctic Peninsula—a key krill fishing area.

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) manages the seas around Antarctica. It will decide on the Weddell Sea sanctuary proposal at a conference in Australia in October, although a decision on the peninsula sanctuary is not expected until later.

Keith Reid, a science manager at CCAMLR, said that the organisation sought “a balance between protection, conservation and sustainable fishing in the Southern Ocean.” He said although more fishing was taking place nearer penguin colonies it was often happening later in the season when these colonies were empty.

“The creation of a system of marine protected areas is a key part of ongoing scientific and policy discussions in CCAMLR,” he added. “Our long-term operation in the region depends on a healthy and thriving Antarctic marine ecosystem, which is why we have always had an open dialogue with the environmental non-governmental organisations. We strongly intend to continue this dialogue, including talks with Greenpeace, to discuss improvements based on the latest scientific data. We are not the ones to decide on the establishment of marine protected areas, but we hope to contribute positively with our knowledge and experience.”