Học tại trường Chưa có thông tin
Đến từ Chưa có thông tin , Chưa có thông tin
Số lượng câu hỏi 10
Số lượng câu trả lời 1
Điểm GP 0
Điểm SP 0

Người theo dõi (0)

Đang theo dõi (0)


Millions of people are using cell phones today. In many places, it is actually considered unusual not to use one. In many countries, cell phones are very popular with young people. They find that the phones are more than a means of communication - having a mobile phone shows that they are cool and connected.

 The explosion in mobile phone use around the world has made some health professionals worried. Some doctors are concerned that in the future many people may suffer health problems from the use of mobile phones. In England, there has been a serious debate about this issue. Mobile phone companies are worried about the negative publicity of such ideas. They say that there is no proof that mobile phones are bad for your health.

 On the other hand, medical studies have shown changes in the brain cells of some people who use mobile phones. Signs of change in the tissues of the brain and head can be detected with modern scanning equipment. In one case, a traveling salesman had to retire at young age because of serious memory loss. He couldn't remember even simple tasks. He would often forget the name of his own son. This man used to talk on his mobile phone for about six hours a day, every day of his working week, for a couple of years. His family doctor blamed his mobile phone use, but his employer's doctor didn't agree.

 What is it that makes mobile phones potentially harmful? The answer is radiation. High-tech machines can detect very small amounts of radiation from mobile phones. Mobile phone companies agree that there is some radiation, but they say the amount is too small to worry about.

 As the discussion about their safety continues, it appears that it's best to use mobile phones less often. Use your regular phone if you want to talk for a long time. Use your mobile phone only when you really need it. Mobile phones can be very useful and convenient, especially in emergencies. In the future, mobile phones may have a warning label that says they are bad for your health. So for now, it's wise not to use your mobile phone too often.

The phrase "negative publicity" in the passage most likely means ____________.

A. poor ideas about the effects of cell phones

B. the negative public use of cell phones

C. widespread opinion about bad effects of cell phones

D. information on the lethal effects of cell phones

Read the following passage and mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the questions from 55 to 64

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

According to the passage, the numerical value of the concentration level of a substance is only useful if _______.

A. it is in a localized area 

B. it can be calculated quickly

C. the natural level is also known 

D. the other substances in the area are known

Read the following passage and mark the letter A,B,C or D on your answer sheet to indicate the word or phrase that best fits each of the blanks.

Until recently, most American entrepreneurs were men. Discrimination against women in business, the demand 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 Doppelt Gray, an official of the Small Business Administration, has noted, “The 1970s were the decade of women entering management, and the 1980s turned out to be the decade of woman 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 excluded from most executive suites. Charlotte Taylor, a management consultant, had noted, “In the 1970s women believed if they got an MBA and 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” field: cosmetic and clothing, for example. But this is changing. Consider ASK computer system, a $22- million-a-year computer 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 newspaper keep tabs on their newspaper carriers-and 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 now 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 situation is changing; there are likely to be many more Sandra Kurtzings in the years ahead.

 

The word “excluded” is closest in meaning to_________.

A. not permitted in

B. often invited to

C. decorators of

D. charged admission to