15000 bài tập tách từ đề thi thử môn Tiếng Anh có đáp án (Phần 63)

In the world to day, particularly in the two most “industrialized areas, North America and Europe, recyling is big news. People are talking about it, practicing it, and discovering new ways to be sensitive to the environment. Recycling means finding was to use products a second time. The motto of the recycling movement is “Reduce, Reuse, Recycle”.

This first step is to reduce garbage. In stores, a shopper has to buy products in blister packs, boxes and expensive plastic wrappings. A hamburger form a fast food restaurant comes in lots of packaging: usually paper, a box, a bag. All that packaging is wasted resources. People should try to buy things that are wrapped simply, and to reuse cups and utensils. Another way to reduce waste is to buy high-quality products. When low quality appliances break, many customers throw them away and buy new ones – a loss of more resources and more energy. For example, if a customer buys a high-quality appliance that can be easily repaired, the manufacturer receives an important message. In the same way, if a customer chooses a product with less packaging, that customer sends an important message to the manufacturers. To reduce garbage, the throwaway must stop.

The second step is to reuse. It is better to buy juices and soft drinks in returnable bottles. After customers empty the bottles, they return them to the store. The manufacturers of the drinks collect the bottles, wash them, and then fill them again. The energy that is necessary to make new bottles is saved. In some parts of the word, returning bottles for money is a common practice. In those places, the garbage dumps have relatively little glass and plastic from throwaway bottles.

The third step is being environmentally sensitive is to recycle. Spent motor oil can be cleaned and used again. Aluminum cans are expensive to make. It takes the same amount of energy to make one aluminum can as it does to run a color TV set for three hours. When people collect and recycle aluminum (for new cans), they help save one of the world’s precious resources.

Telecommuting is some form of computer communication between employees’homes and offices. For employees whose job involve sitting at a terminal or word processor entering data or typing reports, the location of the computer is of no consequence. If the machine can communicate over telephone lines, when the work is completed, employees can dial the office computer and transmit the material to theiremployer. A recent survey in USA Today estimates that there are approximately 8,7 million telecommuters. But although the numbers are rising annually, the trend does not appear to be as significant as predicted when Business Week published “ The Portable Executive” as its cover story a few years ago. Why hasn’t telecommuting become more popular?

    Clearly, change simply takes time. But in addition, there has been active resistance on the part of many managers. These executives claim that supervising the telecommuters in a large work force scattered across the country would be too difficult, or, at least, systems for managing them are not yet developed, thereby complicating the manager’s responsibilities.

    It is also true that employees who are given the option of telecommuting are reluctant to accept the opportunity. Most people feel that they need regular interaction with a group, and many are concerned that they will not have the same consideration for advancement if they are not more visible in the office setting. Some people feel that even when a space in their homes is set aside as a work area, they never really get away from the office.

In addition to providing energy, fats have several other functions in the body. The fat soluble vitamins, A, D, E, and K, are dissolved in fats, as their name implies. Good sources of these vitamins have high oil or fat content, and the vitamins are stored in the body’s fatty tissues. In the diet, fats cause food to remain longer in the stomach, this increasing the feeling of fullness for some time after a meal is eaten. Fats add variety, taste and texture to foods, which accounts for the popularity of fried foods. Fatty deposits in the body have an insulating and protective value. The curves of the human female body are due mostly to strategically located fat deposits.

Whether a certain amount of fat in the diet is essential to human health is not definitely known. When rats are fed a fat-free diet, their growth eventually ceases, their skin becomes inflamed and scaly, and their reproductive systems are damaged. Two fatty acids, linoleic and acids, prevent these abnormalities and hence are called essential fatty acids. They also are required by a number of other animals but their roles in human beings are debatable. Most nutritionists consider linoleic fatty acid an essential nutrient for humans.

An air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely. Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled - a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of the health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions.

Many of the more important air pollutants, such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentration of these pollutants was altered by various chemical reactions; they became components in biogeochemical cycles. These serve as an air purification scheme by allowing the compounds to move from the air to the water or soil. On a global basis, nature's output of these compounds dwarfs that resulting from human activities.

However, human production usually occurs in a localized area, such as a city. In such a region, human output may be dominant and may temporarily overload the natural purification scheme of the cycles. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact, the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, has a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.

The history of clinic nutrition, or the study of the relationship between health and how the body takes in and utilizers food substances, can be divided into four distinct eras: the first began in the nineteenth century and extended into the early twentieth century when it was recognized for the first time that food contained constituents that were essential agents. Near the end of this era, research studies demonstrated that rapid weight loss was associated with nitrogen imbalance and could only be rectified by providing adequate protein associate with certain foods.

          The second era was initiated in the early decades of the twentieth century and might be called "the vitamin period". Vitamins came to be recognized in foods, en deficiency syndromes were described. As vitamins became recognized as essential food constituents necessary for health, it became tempting to suggest that every disease and condition for which there had been no previous effective treatment might be responsive to vitamin therapy. At the point in time, medical schools started to become more interested in having their curricula integrate nutritional therapies in medicine. Reckless claims were made for effects of vitamins that went far beyond what could actually be achieved from the use of them.

          In the third era of nutritional history in the early 1950's to mid-1960's, vitamin therapy began to fall into disrepute. Concomitant with this, nutrition education in medical schools also became less popular. It was just a decade before this that many drug companies had found their vitamins sales skyrocketing and were quick to supply practicing physicians with generous samples of vitamins and literature extolling the virtue of supplementation for a variety health-related conditions. Expectations as to the success of vitamins in disease control were exaggerated. As is known in retrospect, vitamin and mineral therapies are much less effective when applied to health-crisis conditions that when applied to long-term problems of nutrition that lead chronic health problem.

Plants and animals will find it difficult to escape from or adjust to the effect of global warming. Scientists have already observed shifts in the lifecycles of many plants and animals, such as flowers blooming earlier and birds hatching earlier in the spring. Many species have begun shifting where they live or their annual migration patterns due to warmer temperatures.

          With further warming, animals will tend to migrate toward the poles and up mountainsides toward higher elevations. Plants will also attempt to shift their rangers, seeking new areas as old habitats grow too warm. In many places, however, human development will prevent these shifts. Species that find cities of farmland blocking their way north or south may become extinct. Species living in unique ecosystems, such as those found in polar and mountaintop regions, are especially at risk because migration to new habitats is not possible. For instance, polar bears and marine mammals in the Arctic are already threatened by dwindling sea ice but have nowhere father to go.

          Projecting species extinction due to global warming is extremely difficult. Some scientists have estimated that 20 to 50 percent of species could be committed to extinction with 2 to 3 Celsius degrees of further warming. The rate of warming, not just the magnitude, is extremely important for plants and animals. Some species and even entire ecosystems, such as certain types of forest, many not be able to adjust quickly enough and may disappear.

          Ocean ecosystems, especially fragile ones like coral reefs, will also be affected by global warming. Warmer ocean temperatures can cause coral to "bleach", a state which if prolonged will lead to the death of the coral. Scientists estimate that even 1 Celsius degree of additional warming could lead to widespread bleaching and death of coral reefs around the world. Also, increasing carbon dioxide in the atmosphere enters the ocean and increases the acidity of ocean waters. This acidification further stresses ocean ecosystems.

Under the Medicare insurance policy, people approaching 65 may enroll during the seven-month period that includes three months before the sixty-fifth birthday, the month in which the birthday falls, and three months after the birthday. However, if they wish the insurance coverage to begin when they reach 65, they must enroll three months before their birthday. People who do not enroll within their first enrollment period may enroll later, during the first three months of each year. Those people, however, must pay 10% additional for each twelve-month period that elapsed since they first could have enrolled. The monthly premium is deducted from social security payment, railroad retirement or civil service retirement benefits.

May 7, 1840 was the birthday of one of the most famous Russian composers of the nineteenth century Peter Illich Tchaikovsky. The son of a mining inspector, Tchaikovsky studied music as a child and later studied composition at the St.Pertersburg Conservatory. His greatest period of productivity occurred between 1876 and 1890, during which time he enjoyed the patronage of Madame von Meck, a woman he never met, who gave him a living stipend of about $1,000.00 a year. Madame von Meck later terminated her friendship with Tchaikovsky, as well as his living allowance, when she, herself, was facing financial difficulties. It was during the time of Madame von Meck’s patronage, however, that Tchaikovsky created the music for which he is most famous, including the music for the ballets of Swan Lake and The Sleeping Beauty.

    Tchaikovsky’s music, well known for its rich melodic and sometimes melancholy passages, was one of the first that brought serious dramatic music to dance. Before this, little attention had been given to the music behind the dance. Tchaikovsky died on November 6,1893, ostensibly of cholera, though there are now some scholars who argue that he committed suicide.

Carbohydrates, which are sugars, are an essential part of a healthy diet. They provide the main source of energy for the body, and they also function to flavor and sweeten foods. Carbohydrates range from simple sugars like glucose to complex sugars such as amylose ans amylopectin. Nutritionists estimate that carbohydrates should make up about one-fourth to one-fifth of a person’s diet. This translates to about 75-100 grams of carbohydrates per day.

          A diet that is deficient in carbohydrates can have an adverse effect on a person’s health. When the  body lacks a sufficient amount of carbohydrates, it must then use its protein supplies for energy, a process called gluconeogenesis. This, however, results in a lack of necessary protein, and further health difficulties may occur. A lack of carbohydrates can also lead to ketosis, a build-up of ketones in the body that causes fatigue, lethargy, and bad breath.

Until recently, most American entrepreneurs were men. Discrimination against women in business, the demands of caring for families, and lack of business training had kept the number of women entrepreneurs small. Now, however, businesses owned by women account for more than $40 billion in annual revenues, and this figure is likely to continue rising throughout the 1990s. as Carolyn Doppe;t Gray, an offical of the Small Business Administration, has noted, “The 1970s was the decade of women entering management, and the 1980s turned out to be the decade pf the women entrepreneur”. What are some of the factors behind this trend? For one thing, as more women earn advanced degrees in business and enter the corporate world, they are finding obstacles. Women are still excuded from most executive suites. Charlotte Taylor, a management consultant, had noted, “In the 1970s, women believed if they got an MBA anf worked hard, they could become chairman of the board. Now they’ve found out that isn’t going to happen, so they go out on their own.”

           In the past, most women entrepreneurs worked in “women’s” fields: cosmetics and clothing, for example. But this is changing. Consider ASK Computer Systems, a $22-milliona-year computar software business. It was founded in 1973 by Sandra Kurtzig, who was then a housewife with degrees in math and engineering. When Kurtzig founded the business, her first product was software that let weekly newspapers keep tabs on their newspaper carrier sand her office was a bedroom at home, with a shoebox under the bed to hold the company’s cash. After she succeeded with the newspaper software system, she hired several bright computer-science graduates to develop additional programs. When these were marketed and sold, ASK began to grow. It niw has 200 employees, and Sandra Kurtzig owns $66.9 million of stock.

    Of course, many women who start their own businesses fail, just as men often do. They still face hurdles in the business world, especially problems in raising money; the banking and finance world is still dominated by men, and old attitudes die hard. Most businesses owned by women are still quite small. But the situations is changing; there are likely to be many more Sandra Kurtzigs in the years ahead.