1、大学英语六级改革适用（阅读）模拟试卷 236及答案与解析 Section B 0 The Health Benefits of Drinking Water Is bottled drinking water healthier than filtered tap water? A Water is a key ingredient in a healthy diet and lifestyle. There are many health benefits of drinking water. It helps flush impurities and toxins out of our s
2、ystems. It aids in the delivery of oxygen and nutrients. In fact, nearly every system in our bodies relies on water for proper functioning. But what will happen if the water you drink every day is unhealthy? B In past decades, concerns about tap water and its impact on overall health led some people
3、 to turn to bottled drinking water instead However, in those days, there were few choices of bottled waters. You could pay to have a company deliver large bulky plastic bottles of water for the water cooler. Or you could purchase gallon jugs of distilled or “drinking water“ at the grocery store. C I
4、n recent years, there has been an explosion in the number of different bottled waters available, with big distributors such as Coke and Pepsi jumping on the bandwagon. But are bottled drinking waters like Cokes Dasani brand, Pepsis Aquafina, or Wal-Marts store brand really any healthier than your ta
5、p water? Or would you be better off with a drinking water filtration system? D As we have learned more about the water we drink, the technology behind drinking water filters and purification systems has improved dramatically. There are filters to remove impurities, chemicals, heavy metals, bacteria
6、and most every contaminant you can think of. With the right size and filter combination for your specific home, your tap water can be exceptionally pure and healthy. E Drinking water filtration systems have also become more affordable and easy to use. Although the initial cost of a whole house syste
7、m usually amounts to several hundred dollars, that cost is often less than $100 each year if spread out over the life of the system. F There may be additional expenses to replace carbon filters, membranes in reverse osmosis drinking water filtration system, or lamps in an ultraviolet light water tre
8、atment device. These expenses can add another $100 or so to the annual costs of operating drinking water filters and purification systems. G While some people may hesitate to spend so much each year for clean, safe drinking water, they are probably paying more for bottled drinking water. Calculation
9、s show that at a price of $1 to $4 per gallon, bottled or delivered water costs an average of $400 each year, especially if you purchase individual bottles. And that doesnt take into consideration the gas needed to drive to the store or the environmental impact of all the empty plastic bottles. H Ma
10、ny people who choose bottled drinking water understand that it is more expensive, but they are still willing to pay the extra money because bottled water is thought to be safer and healthier than filtered drinking water. After all, bottled water is often marketed as “natural spring water“ or “pure g
11、lacier water.“ I In reality, few bottled waters come from natural springs, and most of them use municipal tap water. The companies are able to get away with this false marketing because the regulations and standards for bottled drinking water are less stringent than those for residential drinking so
12、urces. J The quality of bottled water is regulated by the Food and Drug Administration (FDA), while drinking water systems are typically regulated by State regulations or the Environmental Protection Agency (EPA). This doesnt mean that the FDA isnt doing their job. Its just that the rules for bottle
13、d water only require it to be as good as tap water, not better. K In addition, the FDA regulations only apply to bottled drinking water that is transported across state lines. If a company sells their bottled drinking water in the same state where it was bottled, the federal regulations dont apply.
14、The result is that many bottled waters are not any healthier than filtered water, and in fact some are less pure. L This was demonstrated in a study which was conducted by the Natural Resources Defense Council. They tested over 100 brands of bottled drinking water and found that about one third of t
15、he waters contained contamination in the form of chemicals, bacteria, and arsenic. The study also found that up to forty percent of bottled drinking waters come from a city water system. M So how do you tell if the water you are drinking is healthy? With tap water, it is relatively easy. If your wat
16、er comes from a municipal source, the suppliers are required by law to provide annual water quality reports. If you have a well, you can have an authorized lab test your water. It may cost $100 or more, but its a small price to pay for peace of mind. Or you can purchase a kit and test it yourself, b
17、ut naturally the results may not be as conclusive or reliable as those produced by authorized labs. N When it comes to bottled drinking water, it can be more difficult to know what you are getting. Start by checking the label or the bottle cap. Some may tell you that the water comes from a municipal
18、 source or “community water system,“ which means tap water. O If the label doesnt give any information, you can call the bottler and ask. But dont be surprised if you get the run around and are transferred to several different departments. Some states have a bottled water program that tracks bottled
19、 drinking water and can tell you the origin of the source water as well as other information. P Safe and healthy drinking water has become big business. Thousands of companies are vying for your hard earned cash, and some are not always honest about what their products offer. The initial investment
20、for a home drinking water filtration system can seem expensive at first, but over time, it is usually less expensive than bottled drinking water. And with a water filter, you at least know where the water you drink came from and how it was treated. Q Before going out and spending your hard earned mo
21、ney for bottled drinking water that may be no better than your own tap water, it is obviously a good idea to do some research. You are likely to decide that a drinking water filtration system and/or purifier is the healthier choice and provides the best value as well. 1 For some reasons companies th
22、at use municipal tap water as bottled water can usually escape punishment by law. 2 If you need to know any information about bottled water, you can either ask the bottler for it or get it from the states bottled water program. 3 It is required that suppliers should give yearly water quality reports
23、 for water from a municipal source. 4 In past decades, bottled drinking water was restricted to few choices. 5 A study found that many bottled drinking water was not as healthy as expected. 6 Now, tap water can also become especially pure and healthy if a right filtration system is installed in your
24、 home. 7 One of the disadvantages of bottled water is that the plastic bottles would do harm to the environment. 8 The cost of drinking water filtration system is no more than one hundred dollar each year if we allocate the total expenses equally over the life span of the system. 9 As time goes by,
25、home drinking water filtration system, which may seem expensive at the very beginning, is actually cheaper than bottled drinking water. 10 When the bottled water is claimed to come from a “community water system,“ it is actually tap water. 10 Get Enough Sleep or Else! A good nights sleep is more imp
26、ortant to your health than you may realize. A Megan Jones knew she was tired. Though it had been more than 24 hours since the 25-year-old Vancouverite returned from New Zealand, she was still recovering from jet lag. Jones had left New Zealand on Thursday at 7 a.m., and after a 17-hour flight she ar
27、rived in Vancouver at 7:25 Thursday morning. She forced herself to stay awake all day, hoping to force her body into sleeping through the night. B But getting the sleep she needed didnt prove easy, even though she hadnt slept in nearly 36 hours. “I barely slept that night,“ Jones says. The time chan
28、ge had completely disrupted her sleep pattern, and she wasnt rested when she woke at her usual 8 am. C Jones wasnt aware just how tired she was until two hours later when she set off for the grocery store driving into the lane of oncoming traffic. “Suddenly I knew something wasnt right,“ she says. “
29、I wasnt in New Zealand anymore. I was in Canada driving on the wrong side of the road.“ Luckily she was able to pull back into the right lane without incident. “Theres no question that not getting enough sleep can lead to difficulty in concentrating, says Dr. Jeffrey Lipsitz, medical director for th
30、e Sleep Disorders Centre of Metropolitan Toronto. D Whether the cause is jet lag, shift work, chronic insomnia, a sleep disorder or simply trying to put in extra hours at work, weve all experienced the exhaustion caused by lack of sleep. In fact, sleep is as important to a healthy lifestyle as eatin
31、g properly and exercising. Studies have suggested that too little sleep may increase your risk of heart disease, stroke, diabetes, obesity and depressioa Getting a good nights sleep is one of the simplest things you can do to stay healthy. E A good nights sleep means waking up rested and energized.
32、On average, a healthy adult requires just over eight hours of sleep a night, according to Lipsitz. However, the amount of sleep it takes to achieve rejuvenation varies from person to person. “Its not a fixed number,“ says Joseph De Koninck, professor of psychology at the University of Ottawa, adding
33、 that if you consistently get less than you need, “a sleep deficit accumulates.“ F The time it takes for a sleep deficit to accrue depends on how consistent the problem is, says Dr. Robert Levitan, associate professor of psychiatry at the University of Toronto. “Missing a couple of hours of sleep ev
34、ery night for a week is probably enough.“ G According to studies from Wright State University in Dayton, Ohio, at least one third of adults have significant sleep loss (6.5 hours or less of sleep a night). A recent AC Nielsen poll shows that 19 percent of American adults get six hours or less a nigh
35、t. H Why are we so sleep deprived? “Were so busy that we often dont allow enough time for sleep, says Dr. S.R. Dong of the Westcoast Sleep and Breathing Centre in Burnaby, B.C., who believes lifestyle is the main factor contributing to lack of sleep. According to the most recent General Social Surve
36、y done by Statistics Canada, 47 percent of Canadians will cut back on sleep in order to add time to their days. I Whether its rushing to get the housework done once the kids have gone to bed, attending a social function or working late, were sleeping less than we should. The same survey reveals that
37、 40 per-cent of Canadians report trouble sleeping when theyre severely pressed for time. J For some, the problem lies not in finding the time to sleep but in their inability to fall asleep and stay that way. Sleep disorders, including insomnia (失眠症 ) and sleep apnea (呼吸暂停 ), are often the culprit St
38、atistics Canadas Canadian Community Health Survey says that an estimated 3.3 million Canadians over age 15 suffer from insomnia, and the U.S. National Institutes of Health reports that 70 million Americans suffer from sleep disturbances. K Not sleeping enough can compromise your immune system, says
39、Stanley Coren, author of Sleep Thieves and a professor of psychology at the University of British Columbia. You eat well and exercise in order to keep your immune system up, explains Coren, but if you arent sleeping, you undo all that good work. “The immune system works best when youre asleep,“ he s
40、ays. “Thats when your natural killer cells are generated.“ Natural killer cells are produced in the bone marrow and found in the blood and lymph fluid. L “Natural killer cells are part of the bodys defence mechanism against viruses, bacteria, even cancer, and they do not work properly in the sleep d
41、eprived,“ says Dong. A study at the Cerrahpasa Medical School in Turkey found that after 24 hours of sleep deprivation, the percentage of natural killer cells in the blood declined by 37 percent. A University of California, San Diego, study of 23 males found that one night of partial sleep deprivati
42、on reduced natural-killer-cell activity to 72 percent of normal levels. M Though their activity returns to normal when we begin to get proper sleep, Coren cautions that “the real problem is that a lot of damage might have been done to your body during the time that your immune system left you undefe
43、nded and susceptible to infection.“ N Its not just your immune system that suffers when you cut down on sleep. “There is a higher rate of heart failure among people with sleep disorders and sleep disturbances,“ says Dr. Michael Sole, a cardiologist at the University Health Network in Toronto. Accord
44、ing to Sole, there is increased evidence of Creactive protein, an indicator of heart disease risk, in people suffering from sleep loss. O Researchers at the University of Chicago discovered that chronic sleep loss can reduce the bodys ability to regulate hormones and process carbohydrates. In their
45、study they reduced participants sleep from eight to four hours a night. After less than a week, they noted changes in the body similar to the effects of early diabetes or advanced aging. “Sleep disturbances increase the likelihood of a prediabetic state and obesity,“ says Sole. P Registered dietitia
46、n Ramona Josephson notes that insufficient sleep may affect three hormones that can contribute to obesity. Theres a decrease in leptin, the appetite-suppressing hormone found in our fat tissue, she says. Ghrelin, the hormone controlling hunger pangs, increases with lack of sleep, causing greater fee
47、lings of hunger. And our bodies produce more of the stress hormone Cortisol, which increases fat storage. Not only do the increased hormones resulting from sleep loss cause us to eat more but most of us also make poor food choices when were tired. “The less you sleep, the more chance you have of obe
48、sity,“ Josephson says. Q Sleep is important in keeping not only your waistline trim, but your brain activity balanced as well, says Dr. Robert Levitan. During sleep, brain neurotransmitters the chemicals that deliver messages between nerve cells in the brain are replenished. “When you dont get enoug
49、h sleep, “says Levitan, “your brain chemicals become depleted and that causes emotional disturbances,“ including depression, anxiety, and general feelings of anger or sadness. 11 To maintain a healthy lifestyle, enough sleep, proper eating habits and exercises are equally important. 12 Not enough sleep may have an impact on certain type of hormones, the increase of which may result in a hungrier state and more fat storage. 13 Lack of sleep not only affec
