In the atmosphere, carbon dioxide acts rather like a one-way mirror or the glass in the roof of a greenhouse which allows the sun's rays to enter but prevents the heat from escaping.

　　 According to a weather expert' s prediction, the atmosphere will be 3℃ warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate. If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several metres and severely flooding coastal cities. Also, the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere (北半球), possibly resulting in an alteration of the earth's chief food growing zones.

　　  In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet. But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming, in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels.

　　  Satellite pictures show that large areas of Antarctic ice are already disappearing. The evidence available suggests that a warming has taken place. This fits the theory that carbon dioxide warms the earth.

　　  However, most of the fuel is burnt in the northern hemisphere, where temperatures seem to be falling. Scientists conclude , therefore, that up to now natural influences on the weather have gone beyond those caused by man. The question is: Which natural cause has most effect on the weather?

　　  One possibility is the variable behavior of the sun. Astronomers at one research station have studied the hot spots and "cold" spots (that is, the relatively less hot spots) on the sun. As the sun rotates (使旋转), every 27. 5 days, it presents hotter or "colder" faces to the earth, and different aspects to different parts of the earth. This seems to have a considerable effect on the distribution of the earth's atmospheric pressure, and consequently on wind circulation. The sun is also changeable over a long term: its heat output goes up and down in cycles, the latest trend being downward.

　　  Scientists are now finding shared relations between models of solar weather interactions and the actual climate over many thousands of years, including the last Ice Age. The problem is that the models are predicting that the world should be entering a new Ice Age and it is not. One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia (惯性) of the earth's climate. If this is right, the warming effect of carbon dioxide might thus be serving as a useful opposed balance to the sun's fading heat .

66. It can be concluded that a concentration of carbon dioxide in the atmosphere would_________.

   A. mean a warming-up in the Antarctic

   B. raise the temperature of the earth' s surface

C. prevent the sun's rays from reaching the earth's surface

D. explain the cause of  great changes in the climate in the northern hemisphere

67.The article was written to explain ___________. 

A. the greenhouse effect

B. the solar effects on the earth

C. the causes affecting weather

D. the models of solar-weather interactions

68. Although the fuel consumption is greater in the northern hemisphere, temperatures there　seem to be falling. This is__________.

 A. mainly because the levels of carbon dioxide are rising

 B. partly due to changes in the output of solar energy

C. possibly because the ice caps in the poles are melting

D. only due to the effect of the inertia of the earth' s climate

69. On the basis of their models, scientists believe the opinion that__________.

A. the climate of the world should be becoming cooler

B. the new Ice Age will be delayed by the greenhouse effect

C. the man-made warming effect helps to increase the solar effects

D. it will take thousands of years for the inertia of the earth's climate to take effect

70. If the assumption about the delay of a new Ice age is correct, ____________.

A. ice would soon cover the northern hemisphere

B. the greenhouse effect could work in favor of the earth

C. the best way to overcome the cooling effect would be to burn more fuels

D. the increased levels of carbon dioxide in the atmosphere could warm up the earth even more quickly

D

　　In the atmosphere,carbon dioxide actd rather like a one-way mirror or the glass in the roof of a greenhouse which allows the sun's rays to enter but prevents the heat from excaping.

　　According to a weather expert's prediction,the atmosphere will be 3 warmer in the year 2050 than it is today, if man continues to burn luels at the present rate. If this warming up took place,the ice caps in the poles would begin to melt,thus raising sea level several meters and severely flooding coastal cities.Also，the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere(半球),psooicbly resulting in an alteration of earth's chief food growing zones.

　　In the past,concern about a man - made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet.But the weather experts are now paying more attention to West Antarctic,which may be affected by a warming on the scale that will possibly take place in the next fifty years from on burning of fuels.

　　Satellite pictures showthat large areas of Antarctic ice are already disappearing.The evidence available suggests that a warming has taken place.This fits the theory that carbon dioxide warms the earth.

　　However,most of the fuel is burnt in the northern hemisphere,where temperatures seem to be falling.Scientists conclude,therefore,that up to now natural influences on the weather have exceeded those caused by man.The question is:Which natural cause has most effect on the weather?

　　One possibility is the variable behavior of the sun.Astronomers at one research station have studied the hot spots and cold spots(that is,the relatively less hot spots) on the sun. As the sun rotates(旋转),every 27.5 days,it presents hotter or colder faces to the earth,and different aspects to different parts of the earth.This seems to have a considerable effect on the distribution of the earth's atmospheric pressure,and consequently on wind circulation.The sun is also variable over a long term:its heat output goes up and down in cycles,the latest trend being downward.

　　Scientists are now finding mutual relations between models of solar weather interactions and the actual climate over many thousands of years ,including the last Ice Age.The problem is that the models are predicting that the world should be entering a new Ice Age and it is not.

　　One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia(不活动，惰性) of the earth's climate.If this is right,the warming effect of carbon dioxide might thus be serving as a useful counter balance to the sun's diminishing heat.

　　68.It can be concluded that a concentration of carbon dioxide in the atmosphere would ___.

　　　A.mean a warming - up im the Arctic

　　　B.raise the temperature of the earth's surface

　　　C.prevent the sun's rays from reaching the earth's surface

　　　D.account for great changes in the climate in the northern hemiphere

　　69.Although the fuel consumption is greater in the northern hemisphere,temperatures there seem to be falling.This is _______.

　　　A.mainly because the levels of carbon dioxide are rising

　　　B.partly due to variations in the output of solar energy

　　　C.possibly because the ice caps in the poles are melting

　　　D.exclusively due to the effect of the inertia of the earth's climate

　　70.On the basis of their models,scientists are of the opinion that ________.

　　　A.the climate of the world should be becoming cooler

　　　B.the new Ice Age will be delayed by the greenhouse effect

　　　C.the man - made warming effect helps to increase the solar effects

　　　D.it will take thousands of years for the inertia of the earth's climate to take effect

The temperature is rising again in the Arctic. The sea ice area has dropped to one of the lowest levels on record， climate scientists reported last week.

“The new Arctic Report Card tells a story of widespread and continued effects of a warming Arctic，” said Jackie Richter-Menge of the US’s Cold Regions Research and Engineering Laboratory.

“This isn’t just a climatological (气候学的) effect. It impacts the people that live there，” she added.

Scientists concerned about global warming focus on the Arctic because that is a region where the effects are expected to be felt first， and that has been the case in recent years.

There was a slowdown in Arctic warming in 2009， but in the first half of 2010 warming was near a record pace. The monthly readings were over 4 degrees Celsius above normal in northern Canada， according to the report card. The report card was prepared by 69 researchers in eight countries.

Researchers said last winter’s big snow storms that struck some Northern countries were tied to higher Arctic temperatures.

“Normally the cold air is bottled up in the Arctic，” said Jim Overland of the US National Oceanic and Atmospheric Administration. “But last December and February， winds that normally blow west to east across the Arctic were instead bringing the colder air south，” he said.

“As we lose more sea ice... warming in the atmosphere can create more of these winter storms，” Overland said.

There is a powerful connection between ice cover and air temperatures， Richter-Menge explained. When temperatures warm， ice melts. When ice melts it shows darker surfaces underneath ， which absorb  more heat. “That， in turn， causes more melting and on the cycle goes，” she said.

In September the Arctic sea ice extent was the third smallest in the last 30 years， added Don Perovich of the US Army Laboratory. He said the three smallest ice covers have occurred in the last four years.

1.Scientists care so much about the warming in the Arctic region because 　　　　.

A .the climate in the Arctic doesn’t change much

B. global warming effects are most serious in the Arctic region

C .there has been a major decrease of Arctic warming in recent years

D. by studying the region they can make predictions about the future impact of global warming

2.. Which of the following shows that the Arctic is getting warmer？ 

A. The surface of the sea ice in Arctic is getting darker and darker.

B. The Arctic sea ice extent has disappeared over the last 30 years.

C. The sea ice extent has increased to one of the highest levels on record.

3. What does the underlined word “cycle” refer to？  

A .Ice giving off heat when it melts.

B. Higher temperatures bringing more storms.

C .The cause and the result of the melting.

D. The life of the people living in the Arctic getting worse.

4. According to researchers what led to big snow storms attacking some Northern countries last winter？                 

A. Higher Arctic temperatures.

B. The melting ice.

C. The cold wind blowing west to east.

D. Cold air bottled up in the Arctic.

5. What is the main point of the article？         

A. Last winter’s big snow-storms.

B. Winds in the Arctic region.

C. Arctic warming and its possible effects.

D. Changes to the life of people living in the Arctic.

D
　　In the atmosphere,carbon dioxide actd rather like a one-way mirror or the glass in the roof of a greenhouse which allows the sun's rays to enter but prevents the heat from excaping.
　　According to a weather expert's prediction,the atmosphere will be 3 warmer in the year 2050 than it is today, if man continues to burn luels at the present rate. If this warming up took place,the ice caps in the poles would begin to melt,thus raising sea level several meters and severely flooding coastal cities.Also，the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere(半球),psooicbly resulting in an alteration of earth's chief food growing zones.
　　In the past,concern about a man - made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet.But the weather experts are now paying more attention to West Antarctic,which may be affected by a warming on the scale that will possibly take place in the next fifty years from on burning of fuels.
　　Satellite pictures showthat large areas of Antarctic ice are already disappearing.The evidence available suggests that a warming has taken place.This fits the theory that carbon dioxide warms the earth.
　　However,most of the fuel is burnt in the northern hemisphere,where temperatures seem to be falling.Scientists conclude,therefore,that up to now natural influences on the weather have exceeded those caused by man.The question is:Which natural cause has most effect on the weather?
　　One possibility is the variable behavior of the sun.Astronomers at one research station have studied the hot spots and cold spots(that is,the relatively less hot spots) on the sun. As the sun rotates(旋转),every 27.5 days,it presents hotter or colder faces to the earth,and different aspects to different parts of the earth.This seems to have a considerable effect on the distribution of the earth's atmospheric pressure,and consequently on wind circulation.The sun is also variable over a long term:its heat output goes up and down in cycles,the latest trend being downward.
　　Scientists are now finding mutual relations between models of solar weather interactions and the actual climate over many thousands of years ,including the last Ice Age.The problem is that the models are predicting that the world should be entering a new Ice Age and it is not.
　　One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia(不活动，惰性) of the earth's climate.If this is right,the warming effect of carbon dioxide might thus be serving as a useful counter balance to the sun's diminishing heat.
　　68.It can be concluded that a concentration of carbon dioxide in the atmosphere would ___.
　　　A.mean a warming - up im the Arctic
　　　B.raise the temperature of the earth's surface
　　　C.prevent the sun's rays from reaching the earth's surface
　　　D.account for great changes in the climate in the northern hemiphere
　　69.Although the fuel consumption is greater in the northern hemisphere,temperatures there seem to be falling.This is _______.
　　　A.mainly because the levels of carbon dioxide are rising
　　　B.partly due to variations in the output of solar energy
　　　C.possibly because the ice caps in the poles are melting
　　　D.exclusively due to the effect of the inertia of the earth's climate
　　70.On the basis of their models,scientists are of the opinion that ________.
　　　A.the climate of the world should be becoming cooler
　　　B.the new Ice Age will be delayed by the greenhouse effect
　　　C.the man - made warming effect helps to increase the solar effects
　　　D.it will take thousands of years for the inertia of the earth's climate to take effect

The temperature is rising again in the Arctic. The sea ice area has dropped to one of the lowest levels on record， climate scientists reported last week.

“The new Arctic Report Card tells a story of widespread and continued effects of a warming Arctic，” said Jackie Richter-Menge of the US’s Cold Regions Research and Engineering Laboratory.

“This isn’t just a climatological (气候学的) effect. It impacts the people that live there，” she added.

Scientists concerned about global warming focus on the Arctic because that is a region where the effects are expected to be felt first， and that has been the case in recent years.

There was a slowdown in Arctic warming in 2009， but in the first half of 2010 warming was near a record pace. The monthly readings were over 4 degrees Celsius above normal in northern Canada， according to the report card. The report card was prepared by 69 researchers in eight countries.

Researchers said last winter’s big snow storms that struck some Northern countries were tied to higher Arctic temperatures.

“Normally the cold air is bottled up in the Arctic，” said Jim Overland of the US National Oceanic and Atmospheric Administration. “But last December and February， winds that normally blow west to east across the Arctic were instead bringing the colder air south，” he said.

“As we lose more sea ice... warming in the atmosphere can create more of these winter storms，” Overland said.

There is a powerful connection between ice cover and air temperatures， Richter-Menge explained. When temperatures warm， ice melts. When ice melts it shows darker surfaces underneath ， which absorb  more heat. “That， in turn， causes more melting and on the cycle goes，” she said.

In September the Arctic sea ice extent was the third smallest in the last 30 years， added Don Perovich of the US Army Laboratory. He said the three smallest ice covers have occurred in the last four years.

Scientists care so much about the warming in the Arctic region because 　　　　.

A .the climate in the Arctic doesn’t change much

B. global warming effects are most serious in the Arctic region

C .there has been a major decrease of Arctic warming in recent years

D. by studying the region they can make predictions about the future impact of global warming

. Which of the following shows that the Arctic is getting warmer？ 

A. The surface of the sea ice in Arctic is getting darker and darker.

B. The Arctic sea ice extent has disappeared over the last 30 years.

C. The sea ice extent has increased to one of the highest levels on record.

What does the underlined word “cycle” refer to？  

A .Ice giving off heat when it melts.

B. Higher temperatures bringing more storms.

C .The cause and the result of the melting.

D. The life of the people living in the Arctic getting worse.

According to researchers what led to big snow storms attacking some Northern countries last winter？                 

A. Higher Arctic temperatures.

B. The melting ice.

C. The cold wind blowing west to east.

D. Cold air bottled up in the Arctic.

What is the main point of the article？         

A. Last winter’s big snow-storms.

B. Winds in the Arctic region.

C. Arctic warming and its possible effects.

D. Changes to the life of people living in the Arctic.