Against the supposition that forest fires in Alaska, Canada and Siberia warm the climate, scientists have discovered that cooling may occur in areas where burnt trees allow more snow to mirror more sunlight into space.
This finding suggests that taking steps to prevent northern forest fires to limit the release of greenhouse gases may warm the climate in northern regions. Usually large fires destroyed forests in these areas over the past decade. Scientists predict that with climate warming, fires may occur more frequently over the next several centuries as a result of a longer fire season. Sunlight taken in by the earth tends to cause warming, while heat mirrored back into space tends to cause cooling.
This is the first study to analyze all aspects of how northern fires influence climate. Earlier studies by other scientists have suggested that fire in northern regions speed up climate warming because greenhouse gases from burning trees and plants are released into the atmosphere and thus trap heat.
Scientists found that right after the fire, large amounts of greenhouse gases entered the atmosphere and caused warming. Ozone（臭氧） levels increased, and ash from the fire fell on far-off sea ice, darkening the surface and causing more radiation from the sun to be taken in. The following spring, however, the land within the area of the fire was brighter than before the fire, because fewer trees covered the ground. Snow on the ground mirrored more sunlight back into space, leading to cooling.
“We need to find out all possible ways to reduce the growth of greenhouse gases in the atmosphere.” Scientists tracked the change in the amount of radiation entering and leaving the climate system as a result of the fire, and found a measurement closely related to the global air temperature. Typically, fire in northern regions occurs in the same area every 80 to 150 years. Scientists, however, found that when fire occurs more frequently, more radiation is lost from the earth and cooling results. Specifically, they determined when fire returns 20 years earlier than predicted, 0.5 watts per square meter of area burned are soaked up by the earth from greenhouse gases, but 0.9 watts per square meter will be sent back into space. The net effect is cooling. Watts are used to measure the rate at which energy is gained or lost from the earth.．According to the new findings, taking steps to prevent northern forest fires may __________.
| A．result in a warming climate |
| B．cause the forest fires to occur more frequently |
| C．lead to a longer fire season |
| D．protect the forests and the environment there |
．The following are all the immediate effects after a forest fire EXCEPT __________.
| A．large amounts of greenhouse gases enter the atmosphere |
| B．the levels of ozone which is a type of oxygen increase |
| C．snow on the ground mirrors more sunlight back into space |
| D．ashes from the fire fall on the ice surface and take in more radiation from the sun |
．Earlier studies about northern forest fires __________.
| A．analyze all aspects of how northern fires influence climate |
| B．indicate that forest fires will pollute the atmosphere |
| C．suggest that people should take measures to protect environment |
| D．suggest that the fires will speed up climate warming |
．The underlined phrase “soak up” in the last paragraph most probably means __________.
| A．released | B．absorbed | C．created | D．distributed |
．From the passage we can draw a conclusion that forest fires in Alaska, Canada and Siberia may ____.
| A．warm the climate as the supposition goes |
| B．allow more snow to reflect more sunlight into space and thus cool the climate |
| C．destroy large areas of forests and pollute the far-off sea ice |
| D．help to gain more energy rather than release more energy |
Although the United States covers so much land and the land produces far more food than the present population needs，its people are by now almost entirely an urban society . Less than a tenth of the people are engaged in agriculture and forestry(林业)，and most of the rest live in or around towns，small and large．Here the traditional picture is changing：every small town may still be very like other small towns，and the typical small town may represent a widely accepted view of the country，but most Americans do not live in small towns any more．Half the population now lives in some thirty metropolitan areas(1arge cities with their suburbs、of more than a million people each—a larger proportion than in Germany or England，let alone France)．The statistics(统计)of urban and rural population should be treated with caution because so many people who live in areas classified as rural travel by car to work in a nearby town each day．As the rush to live out of town continues,rural areas within reach of towns are gradually filled with houses，so that it is hard to say at what moment a piece of country becomes a suburb. But more and more the typical American lives in a metropolitan rather than a small town environment．If now America has 250 million people．how many of them are engaged in agriculture and forestry?
| A．About 25 million． | B．More than 25 million． |
| C．Less than 25 million． | D．Less than 225 million |
Which of the following four countries has the smallest proportion of people living in metropolitan areas?
| A．United States． | B．Germany． | C．France． | D．England． |
What’s the meaning of the word “metropolitan” in the middle of the passage?
| A．Of a large city with its suburbs． | B．Of small and large towns． |
| C．Of urban areas． | D．Of rural areas． |
According to the passage，what can we learn about small towns in the United States?
A Most small towns become gradually crowded
B．Small towns are still similar to each other．
C．As the traditional picture is changing，towns are different．
D .Small towns are turning into large citiesWhy is it hard to say when a piece of country becomes a suburb?
| A．Because they are the same． |
| B．Because the rush takes place too quickly |
| C．Because the process is gradual． |
| D．Because more and more Americans live in metropolitan areas． |
There are stories about two U．S . presidents，Andrew Jackson and Martin Van Buren，which attempt to explain the American English term OK．We don’t know if either story is true，but they are both interesting．
The first explanation is based on the fact that President Jackson had very little education．In fact，he had difficulty reading and writing．When important papers came to Jackson，he tried to read them and then had his assistants explain what they said．If he approved of a paper, he would write “all correct”on it．The problem was that he didn’t know how to spell．So what he really wrote was “ol korekt”．After a while，he shortened that term to “OK”．
The second explanation is based on the place where President Van Buren was born，Kinderhook，New York．Van Buren’s friends organized a club to help him become President .They called the club the Old Kinderhook Club，and anyone who supported Van Buren was called“OK”．The author __________.
| A．believes both of the stories |
| B．doesn’t believe a word of the stories |
| C．is not sure whether the stories are true |
| D．is telling the stories just for fun |
According to the passage，President Jackson_____________.
| A．couldn’t draw up any documents at all |
| B．didn’t like to read important papers by himself |
| C．often had his assistants sign documents for him |
| D．wasn’t good at reading，writing or spelling |
According to the first story, the term “OK”_______________.
| A．was approved of by President Jackson |
| B．was the title of some Official documents |
| C．was first used by President Jackson |
| D．was an old way to spell “all correct’’ |
According to the second story，the term ‘‘OK”_____________.
| A．was the short way to say‘ ‘old Kinderhook Club” |
| B．meant the place where President Van Buren was born |
| C．was the name of Van Buren’s club |
| D．was used to call Van Buren’s supporters in the election |
According to the second story, the term “OK” was first used ______________
| A．by Van Buren |
| B．in a presidential election |
| C．to organize the Old Kinderhook Club |
| D．by the members of the ‘‘Old Kinderhook Club” |
I got my first driver's license(执照)in 1953 by taking driver education in my first year at Central High School in Charlotte，North Carolina. Four years later when it was time to renew my license I was a married woman. Henry and I were living in Baltimore，Maryland. Two weeks before my 20th birthday，Henry drove me to the motor vehicle office on a hot July afternoon. When I got to the office and showed to the man behind the counter my North Carolina driver’ s license，ready to renew，the man told me that I was under age by Maryland law since I was not yet 21.“Mr.Henry Smith，your husband，will have to sign for you，”he said.
I argued，pointing to a very large belly(肚子)of mine，“I am married. I am having a baby. Why should I have to have someone sign for me to drive？”He answered coldly，“It’s the law，madam.”
Henry encouraged me to calm down，just go ahead and get the license and be done with it. “No，” I said. I refused to have him sign for me. So I left without a Maryland license.
I called the North Carolina Motor Vehicle Office and renewed my NC license by mail—using my name Susan Brown. And thus it was for the next twelve years. Since Henry was in the army I could drive under my home state license. By the time Henry left the army we were once again living in Maryland，and I had to take the Maryland driver’ s exam. Since then I just go in and renew every four years—sign the name Susan Brown，have my new picture taken，and walk out with a license to drive.Susan got her first driver’ s license________.
| A．before she got married to Henry |
| B．when she was twenty years old |
| C．after she finished high school |
| D．when she just moved to Maryland |
Susan failed to renew her license the first time in Maryland because________.
| A．she was forbidden to drive by Maryland law |
| B．she lacked driving experience in Maryland |
| C．she was to give birth to a baby soon |
| D．she insisted on signing for herself |
We can infer from the text that in the U.S.________.
| A．American males should serve in the army |
| B．different states may have different laws |
| C．people have to renew their licenses in their home states |
| D．women should adopt their husbands’ family names after marriage |
In the animal kingdom, weakness can bring about aggression in other animals. This sometimes happens with humans also. But I have found that my weakness brings out the kindness in people. I see it every day when people hold doors for me, pour cream into my coffee, or help me to put on my coat. And I have discovered that it makes them happy.
From my wheelchair experience, I see the best in people, but sometimes I feel sad because those who appear independent miss the kindness I see daily. They don’t get to see this soft side of others. Often, we try every way possible to avoid showing our weakness, which includes a lot of pretending. But only when we stop pretending we’ re brave or strong do we allow people to show the kindness that’ s in them.
Last month, when I was driving home on a busy highway, I began to feel unwell and drove more slowly than usual. People behind me began to get impatient and angry, with some speeding up alongside me, horning (按喇叭) or even shouting at me. At that moment，I decided to do something I had never done in twenty-four years of driving. I put on the car flashlights and drove on at a really low speed.
No more angry shouts and no more horns!
When I put on my flashlights, I was saying to the other drivers, “I have a problem here. I am weak and doing the best I can.” And everyone understood. Several times, I saw drivers who wanted to pass. They couldn’t get around me because of the stream of passing traffic. But instead of getting impatient and angry, they waited, knowing the driver in front of them was in some way weak.
Sometimes situations call for us to act strong and brave even when we don’t feel that way. But those are few and far between. More often, it would be better if we don’t pretend we feel strong when we feel weak or pretend that we're brave when we’re scared.The author has discovered that people will feel happy when ________.
| A．they offer their help |
| B．they receive others’ help |
| C．they feel others’ kindness |
| D．they show their weakness |
The author feels sad sometimes because ________.
| A．he has a soft heart |
| B．he relies much on others |
| C．some people pretend to be kind |
| D．some people fail to see the kindness in others |
What did the other drivers do when they saw the flashlights?
| A．They speeded up to pass. |
| B．They waited with patience. |
| C．They tried their best to help. |
| D．They put on their flashlights too. |
In this passage, the author advises us to ________.
| A．handle problems by ourselves |
| B．accept help from others |
| C．admit our weakness |
| D．show our bravery |
Good posture certainly shows good health. It also adds to a body's energy and beauty. The body is not handsome when the back is bent and neck thrusts forward. Bad posture suggests the impression that a person is tired，lacking in energy，bored，or weak. Tiredness may sometimes be the cause of bad posture. Most often，however，it is due to careless and poor health habits. Whatever it causes，bad posture affects one physically. The muscles are stretched and pulled into unnatural positions，which can lead to poor base of the body's various systems.
Nutrition is the study of how the body takes food and uses it. This science provides information about the kinds of food a person must eat to improve and maintain good health. Such knowledge helps him develop and form people habits to his problems of healthful living. People habits of nutrition can be developed by paying attention to:(1) the variety of food included in the diet；(2) the quality of each kind of food eaten. A diet，or the food regularly eaten，must contain all the necessary factors.
Many physicians believe that overweight is one of the greatest dangers to good health. This condition often leads to a shorter life. An overweight person is also easier to suffer disease, and various disorders of the digestive system. A person’s weight directly has something to do with the amounts of food he eats.
All foods can make a person fat if too much is eaten. In reducing，the safe weight loss is about two pounds a week. The sensible way to lose weight is to decrease the gaining starchy(含淀粉的) foods，fats and sweets in the diet.According to this passage, which of the following is suggested about the good health habits?
| A．Good way of holding your body. | B．Balanced food. |
| C．Right body weight. | D．All of the above. |
According to this passage，bad posture is most probably caused by_______.
| A．tiredness，boredom and weakness |
| B．lack of energy |
| C．careless and poor health habits |
| D．overworking and illness |
Which of the following eating habits is NOT proper in terms of maintaining good health?
| A．Vegetables，meat and water only. |
| B．A suitable quantity of each kind of food. |
| C．Fats being part of diet. |
| D．Various foods included in the diet. |
We can infer from the statement “all foods can make a person fat if too much is eaten” that________.
| A．to lose weight you had better eat properly for daily meals |
| B．the most effective way to lose weight is to have no fat and sweet |
| C．even vegetables can make you put on weight , so there is no need to have fat and sweet. |
| D．a shorter life is a sure result of overweight |
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