It was once thought that air pollution affected only the area immediately around large cities with factories and/or heavy automobile traffic. Today, we know that although these are the areas with the worst air pollution, the problem is literally worldwide. On several occasions over the past decade, a heavy cloud of air pollution has covered the entire eastern half of the United States and led to health warnings even in rural areas away from any major concentration of manufacturing and automobile traffic. In fact, the very climate of the entire earth may be affected by air pollution. Some scientists feel that the increasing concentration of carbon dioxide in the air resulting from the burning of fossil fuels(coal and oil) creating a greenhouse effect-holding in heat reflected from the earth and raising the world’s average temperature. If this view is correct and the world’s temperature is raised only a few degrees, much of the polar ice cap will melt and cities such as New York, Boston, Miami, and New Orleans will be under water.

Another view, less widely held, is that increasing particulate matter in the atmosphere is blocking sunlight and lowering the earth’s temperature-a result that would be equally disastrous（灾难的）. A drop of just a few degrees could create something close to a new ice age, and would make agriculture difficult or impossible in many of our top farming areas. At present we do riot know for sure that either of these conditions will happen(though one recent government report prepared by experts in the field concluded that the greenhouse effect is very likely). Perhaps, if we very lucky, the two tendencies will offset each other and the world’s temperature will stay about the same as it is now.

As pointed out at the beginning of the passage, people used to think that air pollution ______.

       A．caused widespread damage in the countryside

       B．affected the entire eastern half of the United States

       C．almost brought worldwide effect

       D．existed merely in urban and industrial areas

As far as the greenhouse effect is concerned, the author _____________.

       A．shares the same view with the scientists

       B．is uncertain of its occurrence

       C．rejects it as being ungrounded（无根据的）

       D．thinks that it will increasingly destroy the world soon

It can be inferred from the passage that                    .

       A．raising the world’s temperature a little would not do much harm to life on the earth

       B．lowering the world’s temperature a little would lead to agricultural disasters

       C．almost no temperature variations have occurred over the past decade

       D．the world’s temperature will remain stable forever

This passage is primarily concerned with              .

       A．the greenhouse effect in the world

       B．the measures to adjust the climate

       C．the potential effect of air pollution

       D．the measures to protect the environment

There was one thought that air pollution affected only the area immediately around large cities with factories and heavy automobile traffic. At present, we realize that although these are the areas with the worst air pollution, the problem is literally worldwide. On several occasions over the past decade, a heavy cloud of air pollution has covered the east of the United States and brought health warnings in rural areas away from any major concentration of manufacturing and automobile traffic. In fact, the very climate of the entire earth may be infected by air pollution. Some scientists consider that the increasing concentration of carbon dioxide in the air resulting from the burning of fossil fuels (coal and oil) is creating a “greenhouse effect”— conserving heat reflected from the earth and raising the world’s average temperature. If this view is correct and the world’s temperature is raised only a few degrees, much of the polar ice cap will melt and cities such as New York, Boston, Miami, and New Orleans will be in water.

Another view, less widely held, is that increasing particular matter in the atmosphere is blocking sunlight and lowering the earth’s temperature — a result that would be equally disastrous. A drop of just a few degrees could create something close to a new ice age, and would make agriculture difficult or impossible in many of our top farming areas. Today we do not know for sure that either of these conditions will happen (though one recent government report drafted by experts in the field concluded that the greenhouse effect is very possible). Perhaps, if we are lucky enough, the two tendencies will offset each other and the world’s temperature will stay about the same as it is now. Driven by economic profits, people neglect the damage on our environment caused by the “advanced civilization”. Maybe the air pollution is the price the human beings have to pay for their development. But is it really worthwhile?

As pointed out at the beginning of the passage, people used to think that air pollution _______.

A. cause widespread damage in the countryside

B. affected the entire eastern half of the United States

C. had damaged effect on health

D. existed merely in urban and industries areas

As to the greenhouse effect, the author __________.

A. share the same view with the scientist.

B. is uncertain of its occurrence

C. rejects it as being ungrounded

D. thinks that it will destroy the world soon

The word “offset” in the second paragraph could be replaced by _________.

A. slip into   B. make up for　　 C. set up    D. catch up with

It can be concluded that ____________.

A. raising the world’s temperature only a few degrees would not do much harm to life on earth

B. lowering the world’s temperature merely a few degrees would lead major farming areas to disaster 

C. almost no temperature variations have occurred over the past decade

D. the world’s temperature will remain constant in the years to come

This passage is primarily about __________.

A. the greenhouse effect        　    B. the burning of fossil fuels

C. the potential effect of air pollution  　D. the likelihood of a new ice age

There was one thought that air pollution affected only the area immediately around large cities with factories and heavy automobile traffic. At present, we realize that although these are the areas with the worst air pollution, the problem is worldwide. On several occasions over the past decade, a heavy cloud of air pollution has covered the east of the United States and brought health warnings in rural areas away from any major concentration （集中）of manufacturing and automobile traffic. In fact, the very climate of the entire earth may be infected by air pollution.

Some scientists consider that the increasing concentration of carbon dioxide in the air resulting from the burning of coal and oil is creating a “greenhouse effect” - raising the world’s average temperature. If this view is correct and the world’s temperature is raised only a few degrees, much of the polar ice will melt and cities such as New York, Boston, Miami, and New Orleans will be in water.

Another view, less widely held, is that increasing particular matter in the atmosphere is preventing sunlight and lowering the earth’s temperature - a result that would be equally disastrous. A drop of just a few degrees could create something close to a new ice age, and would make agriculture difficult or impossible in many of our top farming areas. Today we do not know for sure that either of these conditions will happen though one recent government reports that the greenhouse effect is very possible. Perhaps, if we are lucky enough, the two tendencies will offset（抵消）each other and the world’s temperature will stay about the same as it is now. Driven by economic profits, people don’t think about the damage on our environment caused by the “advanced civilization”. Maybe the air pollution is the price the human beings have to pay for their development. But is it really worth?

As pointed out at the beginning of the passage, people used to think that air pollution ________.

A. caused widespread damage in the countryside

    B. affected the entire eastern half of the United States

    C. had damaged effect on health

    D. existed only in urban and industrial areas

As to the greenhouse effect, the author ________.

    A. shares the same view with the scientists

    B. is uncertain of its happening

    C. rejects it as being ungrounded

    D. thinks it will destroy the world soon

It can be concluded from the last paragraph that ________.

    A. lowering the world’s temperature only a few degrees would lead major farming areas to disaster

    B. raising the world’s temperature only a few degrees would not do much harm to life on earth

    C. almost no temperature variations have occurred over the past decade

    D. the world’s temperature will remain constant in the years to come

This passage is mainly about ________.

    A. the greenhouse effect

    B. the burning of coal and oil

    C. the potential effect of air pollution

    D. the likelihood of a new ice age

It was once thought that air pollution affected only the area immediately around large cities with factories and/or heavy automobile traffic. Today, we know that although these are the areas with the worst air pollution, the problem is actually worldwide. On several occasions over the past decade, a heavy cloud of air pollution has covered the entire eastern half of the United States and led to health warnings even in rural areas away from any major concentration of manufacturing and automobile traffic. In fact, the very climate of the entire earth may be affected by air pollution. Some scientists feel that the increasing concentration of carbon dioxide in the air resulting from the burning of fossil fuels (coal and oil) is creating a “greenhouse effect" - holding in heat reflected from the earth and raising the world's average temperature. If this view is correct and the world's temperature is raised only a few degrees, much of the polar ice cap will melt and cities such as New York, Boston, Miami, and New Orleans will be under water.

Another view, less widely held, is that increasing particulate (废气排往空中而形成的微粒、颗粒) matter in the atmosphere is blocking sunlight and lowering the earth's temperature ─ a result that would be equally disastrous. A drop of just a few degrees could create something close to new ice age and would make agriculture difficult or impossible in many of our top farming areas. At present we do not know for sure that either of these conditions will happen (though one recent government report prepared by experts in the field concluded that the greenhouse effect is very likely). Perhaps, if we are very lucky, the two tendencies will offset each other and the world's temperature will stay about the same as it is now.

As pointed out at the beginning of the passage, people used to think that air pollution ______.

    A. caused widespread damage in the countryside

    B. affected the entire eastern half of the United States

    C. had damaging effects on health

    D. existed merely in urban and industrial areas

As far as the greenhouse effect is concerned, the author ______.

    A. shares the same view with the scientists

    B. is uncertain of its occurrence

    C. rejects it as being ungrounded

    D. thinks that it will destroy the world soon

The underlined word “offset" in Para. 2 could best be replaced by______.

    A. slip into    B. make up for  C. set up   D. catch up with

This passage is mainly concerned with ______.

    A. the greenhouse effect                B. the burning of fossil fuels

    C. the potential effect of air pollution    D. the possibility of a new ice age

It was once thought that air pollution affected only the area immediately around large cities with factories and/or heavy automobile traffic. Today, we know that although these are the areas with the worst air pollution, the problem is actually worldwide. On several occasions over the past decade, a heavy cloud of air pollution has covered the entire eastern half of the United States and led to health warnings even in rural areas away from any major concentration of manufacturing and automobile traffic. In fact, the very climate of the entire earth may be affected by air pollution. Some scientists feel that the increasing concentration of carbon dioxide in the air resulting from the burning of fossil fuels (coal and oil) is creating a “greenhouse effect" - holding in heat reflected from the earth and raising the world's average temperature. If this view is correct and the world's temperature is raised only a few degrees, much of the polar ice cap will melt and cities such as New York, Boston, Miami, and New Orleans will be under water.

Another view, less widely held, is that increasing particulate (废气排往空中而形成的微粒、颗粒) matter in the atmosphere is blocking sunlight and lowering the earth's temperature ─ a result that would be equally disastrous. A drop of just a few degrees could create something close to new ice age and would make agriculture difficult or impossible in many of our top farming areas. At present we do not know for sure that either of these conditions will happen (though one recent government report prepared by experts in the field concluded that the greenhouse effect is very likely). Perhaps, if we are very lucky, the two tendencies will offset each other and the world's temperature will stay about the same as it is now.

As pointed out at the beginning of the passage, people used to think that air pollution ______.

       A. caused widespread damage in the countryside

       B. affected the entire eastern half of the United States

       C. had damaging effects on health

       D. existed merely in urban and industrial areas

As far as the greenhouse effect is concerned, the author ______.

       A. shares the same view with the scientists

       B. is uncertain of its occurrence

       C. rejects it as being ungrounded

       D. thinks that it will destroy the world soon

The underlined word “offset" in Para. 2 could best be replaced by______.

       A. slip into    B. make up for       C. set up        D. catch up with

This passage is mainly concerned with ______.

       A. the greenhouse effect                   B. the burning of fossil fuels

       C. the potential effect of air pollution        D. the possibility of a new ice age