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.
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.

According to the passage, what makes mobile phones potentially harmful is ____________.




A.their power of attraction
B.their raiding power
C.their radiant light
D.their invisible rays

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Read the following pasage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions
As heart disease continues to be the number-one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks. High-fat diets and "life in the fast lane" have long been known to contribute to the high incidence of heart failure. But according to new studies, the list of risk factors may be significantly longer and quite surprising.
Heart failure, for example, appears to have seasonal and temporal patterns. A higher percentage of heart attacks occur in cold weather, and more people experience heart failure on Monday than on any other day of the week. In addition, people are more susceptible to heart attacks in the first few hours after waking. Cardiologists first observed this morning phenomenon in the mid-1980, and have since discovered a number of possible causes. An early-morning rise in blood pressure, heart rate, and concentration of heart stimulating hormones, plus a reduction of blood flow to the heart, may all contribute to the higher incidence of heart attacks between the hours of 8:00 A.M. and 10:00 A.M.
In other studies, both birthdays and bachelorhood have been implicated as risk factors. Statistics reveal that heart attack rates increase significantly for both females and males in the few days immediately preceding and following their birthdays. And unmarried men are more at risk for heart attacks than their married counterparts. Though stress is thought to be linked in some way to all of the aforementioned risk factors, intense research continues in the hope of further comprehending why and how heart failure is triggered.
According to the passage, which of the following is NOT a possible cause of any heart attacks?




A.Decreased blood flow to the heart
B.Increased blood pressure
C.Lower heart rate
D.Increase in hormones

Read the following pasage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions
As heart disease continues to be the number-one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks. High-fat diets and "life in the fast lane" have long been known to contribute to the high incidence of heart failure. But according to new studies, the list of risk factors may be significantly longer and quite surprising.
Heart failure, for example, appears to have seasonal and temporal patterns. A higher percentage of heart attacks occur in cold weather, and more people experience heart failure on Monday than on any other day of the week. In addition, people are more susceptible to heart attacks in the first few hours after waking. Cardiologists first observed this morning phenomenon in the mid-1980, and have since discovered a number of possible causes. An early-morning rise in blood pressure, heart rate, and concentration of heart stimulating hormones, plus a reduction of blood flow to the heart, may all contribute to the higher incidence of heart attacks between the hours of 8:00 A.M. and 10:00 A.M.
In other studies, both birthdays and bachelorhood have been implicated as risk factors. Statistics reveal that heart attack rates increase significantly for both females and males in the few days immediately preceding and following their birthdays. And unmarried men are more at risk for heart attacks than their married counterparts. Though stress is thought to be linked in some way to all of the aforementioned risk factors, intense research continues in the hope of further comprehending why and how heart failure is triggered.
The word “trigger” as used in the first paragraph is closest in meaning to which of the following?




A.involve
B.affect
C.cause
D.encounter

Read the following pasage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions
Garbage cans are not magical portals. Trash does not disappear when you toss it in a can. Yet, the average American throws away an estimated 1,600 pounds of waste each year. If there are no magic garbage fairies, where does all that trash go? There are four methods to managing waste: recycling, landfilling, composting, and incinerating. Each method has its strengths and weaknesses. Let's take a quick look at each.
Recycling is the process of turning waste into new materials. For example, used paper can be turned into paperboard, which can be used to make book covers. Recycling can reduce pollution, save materials, and lower energy use. Yet, some argue that recycling wastes energy. They believe that collecting, processing, and converting waste uses more energy than it saves. Still, most people agree that recycling is better for the planet than landfilling.
Landfilling is the oldest method of managing waste. In its simplest form, landfilling is when people bury garbage in a hole. Over time the practice of landfilling has advanced. Garbage is compacted before it is thrown into the hole. In this way more garbage can fit in each landfill. Large liners are placed in the bottom of landfills so that toxic garbage juice doesn't get into the ground water. Sadly, these liners don't always work. Landfills may pollute the local water supply. Not to mention that all of that garbage stinks. Nobody wants to live next to a landfill. This makes it hard to find new locations for landfills.
Compositing is when people pile up organic matter, such as food waste, and allow it to decompose. The product of this decomposition is compost. Compost can be added to the soil to make the soil richer and better for growing crops. While composting is easy to do onsite somewhere, like home or school, it's hard to do after the garbage gets all mixed up. This is because plastic and other inorganic materials must be removed from the compost pile or they will pollute the soil. There's a lot of plastic in garbage, which makes it hard to compost on a large scale.
One thing that is easier to do is burning garbage. There are two main ways to incinerate waste. The first is to create or harvest a fuel from the waste, such as methane gas, and burn the fuel. The second is to burn the waste directly. The heat from the incineration process can boil water, which can power steam generators. Unfortunately, burning garbage pollutes the air. Also, some critics worry that incinerators destroy valuable resources that could be recycled.
Usually, the community in which you live manages waste. Once you put your garbage in that can, what happens to it is beyond your control. But you can make choices while it is still in your possession. You can choose to recycle, you can choose to compost, or you can choose to let someone else deal with it. The choice is yours.
According to the passage how many main ways to incinerate waste?




A.one
B.three
C.two
D.four

Read the following pasage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions
Any list of the greatest thinkers in history contains the name of the brilliant physicist Albert Einstein. His theories of relativity led to entirely new ways of thinking about time, space, matter, energy, and gravity. Einstein's work led to such scientific advances as the control of atomic energy, even television as a practical application of Einstein's work.
In 1902 Einstein became an examiner in the Swiss patent office at Bern. In 1905, at age 26, he published the first of five major research papers. The first one provided a theory explaining Brownian movement, the zig-zag motion of microscopic particles in suspension. The second paper laid the foundation for the photon, or quantum, theory of light. In it he proposed that light is composed of separate packets of energy, called quanta or photons, that have some of the properties of particles and some of the properties of waves. A third paper contained the "special theory of relativity" which showed that time and motion are relative to the observer, if the speed of light is constant and the natural laws are the same everywhere in the universe. The fourth paper was a mathematical addition to the special theory of relativity. Here Einstein presented his famous formula, E = m(cc), known as the energy mass equivalence. In 1916, Einstein published his general theory of relativity. In it he proposed that gravity is not a force, but a curve in the space-time continuum, created by the presence of mass. Einstein spoke out frequently against nationalism, the exalting of one nation above all others. He opposed war and violence and supported Zionism, the movement to establish a Jewish homeland in Palestine. When the Nazis came to power in 1933, they denounced his ideas. He then moved to the United States. In 1939 Einstein learned that two German chemists had split the uranium atom. Einstein wrote to President Franklin D. Roosevelt warning him that this scientific knowledge could lead to Germany developing an atomic bomb. He suggested the United States begin its own atomic bomb research.
According to Einstein, light is composed of separate packets of energy called




A.electrons
B.photoelectrons
C.gamma rays
D.quanta