Man must stop_______the earth’s atmosphere.A.filling B.wasting C.polluting D.blackening

Passage 2
If the population of the earth goes on increasing at its present rate, there will eventually not be enough resources left to sustain life on the planet. By the middle of the 21st century, if present trends continue, we will have used up all the oil that drives our cars, for example. Even if scientists develop new ways of feeding the human race, the crowded conditions on earth will make it necessary for us to look for open space somewhere else. But none of the other planets in our solar system are capable of supporting life at present. One possible solution to the problem, however, has recently been suggested by an American scientist, Professor Carl Sagan.
Sagan believes that before the earth's resources are completely exhausted it will be possible to change the atmosphere of Venus and so create a new world almost as large as earth itself. The difficulty is that Venus is much hotter than the earth and there is only a tiny amount of water there.
Sagan proposes that algae organisms, which can live in extremely hot or cold atmospheres and at the same time produce oxygen, should be bred in conditions similar to those on Venus. As soon as this has been done, the algae will be placed in small rockets. Spaceships will then fly to Venus and fire the rockets into the atmosphere. In a fairly short time, the algae will break down the carbon dioxide into oxygen and carbon.
When the algae have done their work, the atmosphere will become cooler, but before man can set foot on Venus it will be necessary for the oxygen to produce rain. The surface of the planet will still be too hot for men to land on it but the rain will eventually fall and in a few years something like earth will be reproduced on Venus.
On Venus there is a lot of__________.

A. water
B. carbon dioxide
C. carbon monoxide
D. oxygen

Passage 2
If the population of the earth goes on increasing at its present rate, there will eventually not be enough resources left to sustain life on the planet. By the middle of the 21st century, if present trends continue, we will have used up all the oil that drives our cars, for example. Even if scientists develop new ways of feeding the human race, the crowded conditions on earth will make it necessary for us to look for open space somewhere else. But none of the other planets in our solar system are capable of supporting life at present. One possible solution to the problem, however, has recently been suggested by an American scientist, Professor Carl Sagan.
Sagan believes that before the earth's resources are completely exhausted it will be possible to change the atmosphere of Venus and so create a new world almost as large as earth itself. The difficulty is that Venus is much hotter than the earth and there is only a tiny amount of water there.
Sagan proposes that algae organisms, which can live in extremely hot or cold atmospheres and at the same time produce oxygen, should be bred in conditions similar to those on Venus. As soon as this has been done, the algae will be placed in small rockets. Spaceships will then fly to Venus and fire the rockets into the atmosphere. In a fairly short time, the algae will break down the carbon dioxide into oxygen and carbon.
When the algae have done their work, the atmosphere will become cooler, but before man can set foot on Venus it will be necessary for the oxygen to produce rain. The surface of the planet will still be too hot for men to land on it but the rain will eventually fall and in a few years something like earth will be reproduced on Venus.
CarlSagan believes that Venus might be colonized from earth because__________.

A. it might be possible to change its atmosphere
B. its atmosphere is the same as the earth's
C. there is a good supply of water on Venus
D. the days on Venus are long enough

共用题干
第三篇

Preserve the Environment

Throughout history man has changed his physical environment in order to improve his way of life.
With the tools of technology he has altered many physical features of the earth.He has transformed
woodlands into farmland,and made lakes and reservoirs out of rivers for irrigation purposes or hydroelectric
power. Man has also modified the face of the earth by draining marshes and cutting through mountains to
build roads and railways.
However,man's changes to the physical environment have not always had beneficial results.Today,
pollution of the air and water is an increasing danger to the health of the planet.Each day thousands of tons
of gases come out of the exhausts of motor vehicles;smoke from factories pollutes the air of industrialized areas
and the surrounding areas of countryside.The air in cities is becoming increasingly unhealthy.
The pollution of water is equally harmful.In the sea,pollution from oil is increasing and is killing enor-
mous numbers of algae（水藻）,fish and birds.The whole ecological balance of the sea is being changed.
The same problem exists in rivers.Industrial wastes have already made many rivers lifeless.
Conservationists believe that it is now necessary for man to limit the growth of technology in order to sur-
vive on earth.

The purpose of the writer is___________.
A:to reduce modern technology
B:to improve man's way of life
C:to warn people not to change the natural environment
D:to call attention to the protection of the natural environment

共用题干
To Survive or to Vanish

1.Over 3.6 billion years ago,the first creature was born in the world.Since then,the earth started its era with life.The history of life on earth has been a history of interaction between living things and their surroundings.To a large extent,the physical form and the habits of the earth's vegetation and its animal life have been molded by the environment. Considering the whole span of earthly time,the opposite effect,in which life actually modifies its surroundings,has been relatively slight. Only in the present century has one species一man acquired significant power to alter the nature of his world.
2.During the past 25 years,this power has not only become increasingly great but it has changed in character. The most alarming of all man's assaults upon the environment is the contamination of air,earth,rivers,and sea with dangerous and even lethal materials. This pollution is for the most part irrecoverable.In this now universal contamination of the environment,chemicals are the sinister partners of radiation in changing the very nature of the world the very nature of its life. Chemicals sprayed on croplands or forests or gardens lie long in soil,entering into living organisms, passing from one to another in a chain of poisoning and death.Or they pass mysteriously by underground streams until they emerge and combine into new forms that kill vegetation,sicken cattle,and work unknown harm on those who drink from once pure wells."Man can hardly even recognize the devils of his own creation,"as a scientist has said.
3.Hundreds of millions of years have passed before the globe produced the life that now inhabits the earth.Given time not in years but in millennia life adjusts,and a balance has been reached.But in the modern world there is no time.
4.The quick steps of change follows the impetuous pace of man rather than the deliberate pace of nature.Radiation is now the unnatural creation of man's tampering with the atom.The chemicals are the synthetic creations of man's inventive mind,having no counterparts in nature.
5.To survive these chemicals would require not merely the years of one man's life but the life of generations.And even this,were it by some miracle possible,would be futile,for the new chemicals come from our laboratories in an endless stream;almost five hundred annually find their way into actual use in the United States alone.Among them are many that are used in man's war against nature.Since the mid l940's over 200 basic chemicals have been created for use in killing insects,weeds,and other organisms described as"pests".
6.It is not my contention that chemical insecticides must never he used.I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these poisons,without their consent and often without their knowledge.I contend,furthermore,that we have allowed these chemicals to be used with little or no advance investigation of their effect on soil,water,wildlife,and man himself. Future generations are unlikely to forgive our lack of concern for the integrity of the natural world that supports all life.

Human's pollution on nature is for the most part_______.
A:man's tampering with the atom
B:enormous numbers of people to contact with these poisons
C:the integrity of the natural world that supports all life
D:inventive
E:irrecoverable
F:relatively slight

共用题干
To Survive or to Vanish

1.Over 3.6 billion years ago,the first creature was born in the world.Since then,the earth started its era with life.The history of life on earth has been a history of interaction between living things and their surroundings.To a large extent,the physical form and the habits of the earth's vegetation and its animal life have been molded by the environment. Considering the whole span of earthly time,the opposite effect,in which life actually modifies its surroundings,has been relatively slight. Only in the present century has one species一man acquired significant power to alter the nature of his world.
2.During the past 25 years,this power has not only become increasingly great but it has changed in character. The most alarming of all man's assaults upon the environment is the contamination of air,earth,rivers,and sea with dangerous and even lethal materials. This pollution is for the most part irrecoverable.In this now universal contamination of the environment,chemicals are the sinister partners of radiation in changing the very nature of the world the very nature of its life. Chemicals sprayed on croplands or forests or gardens lie long in soil,entering into living organisms, passing from one to another in a chain of poisoning and death.Or they pass mysteriously by underground streams until they emerge and combine into new forms that kill vegetation,sicken cattle,and work unknown harm on those who drink from once pure wells."Man can hardly even recognize the devils of his own creation,"as a scientist has said.
3.Hundreds of millions of years have passed before the globe produced the life that now inhabits the earth.Given time not in years but in millennia life adjusts,and a balance has been reached.But in the modern world there is no time.
4.The quick steps of change follows the impetuous pace of man rather than the deliberate pace of nature.Radiation is now the unnatural creation of man's tampering with the atom.The chemicals are the synthetic creations of man's inventive mind,having no counterparts in nature.
5.To survive these chemicals would require not merely the years of one man's life but the life of generations.And even this,were it by some miracle possible,would be futile,for the new chemicals come from our laboratories in an endless stream;almost five hundred annually find their way into actual use in the United States alone.Among them are many that are used in man's war against nature.Since the mid l940's over 200 basic chemicals have been created for use in killing insects,weeds,and other organisms described as"pests".
6.It is not my contention that chemical insecticides must never he used.I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these poisons,without their consent and often without their knowledge.I contend,furthermore,that we have allowed these chemicals to be used with little or no advance investigation of their effect on soil,water,wildlife,and man himself. Future generations are unlikely to forgive our lack of concern for the integrity of the natural world that supports all life.

Paragraph 1_______
A:Man should be cautious in chemical use.
B:It takes generations for mankind to adapt themselves to the chemicals.
C:Chemicals are human's invention
D:Human's power increases and has changed its character in the past quarter century.
E:The new change in the relationship between earth and its creature一human's power playing a greater role in changing the world
F: Modern world gives no time for nature to adjust to human.

共用题干
Early Ideas about the Universe

1 Early man got his ideas about the universe by looking at the stars as you do.He
observed carefully,and learned many things about the sun,the moon,and the stars.
2 Suppose you were asked to collect evidence about the sun as early man did.You might
go out morning after morning and see it come up in the east.Even on cloudy mornings,you
would observe that the darkness goes away and the world becomes light.You might not see
the sun but would be sure it is there,because you notice that the earth warms up.As you
continued,the sun climbs higher in the sky each day during part of the year. It stays in the
sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.
3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin
to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell
exactly why it happens.But you realize that the sun seems to make the difference.
Primitive（原始的）man felt that since the sun was so powerful it must be a god. It may
seem silly to us now to worship（崇拜）a sun-god, but primitive man was right about the
importance of the sun to life on earth.
4 You have been told that the world is round.But suppose no one had ever taught you
that the world was like a huge ball.Would you have ever thought of it yourself?You cannot
see the curve（曲线）of the earth at once. You would have no idea of how big it was.
That's why early man believed that the earth was small and flat.Such ideas appeared from
the evidence they had.
5 If you watch the stars night after night,you will see them rise and set.As you look at
the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling
（闪烁）lights. Some early astronomers（天文学家）believed the sky was a crystal shell or
series of crystal shells,one inside the other. They believed this because that is what the
night sky looked like.For many centuries,men believed that the earth was the center of
the universe and that the sun,the moon,and the stars circled around it.

Early man thought the earth was small and flat because_________.
A:he did not observe the sun carefully enough
B:he could not see its curve
C:the sun,the moon and the stars seemed to move around it
D:the earth circles around the sun
E:it looked like that at night
F:it has power over life on earth

共用题干
Early Ideas about the Universe

1 Early man got his ideas about the universe by looking at the stars as you do.He
observed carefully,and learned many things about the sun,the moon,and the stars.
2 Suppose you were asked to collect evidence about the sun as early man did.You might
go out morning after morning and see it come up in the east.Even on cloudy mornings,you
would observe that the darkness goes away and the world becomes light.You might not see
the sun but would be sure it is there,because you notice that the earth warms up.As you
continued,the sun climbs higher in the sky each day during part of the year. It stays in the
sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.
3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin
to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell
exactly why it happens.But you realize that the sun seems to make the difference.
Primitive（原始的）man felt that since the sun was so powerful it must be a god. It may
seem silly to us now to worship（崇拜）a sun-god, but primitive man was right about the
importance of the sun to life on earth.
4 You have been told that the world is round.But suppose no one had ever taught you
that the world was like a huge ball.Would you have ever thought of it yourself?You cannot
see the curve（曲线）of the earth at once. You would have no idea of how big it was.
That's why early man believed that the earth was small and flat.Such ideas appeared from
the evidence they had.
5 If you watch the stars night after night,you will see them rise and set.As you look at
the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling
（闪烁）lights. Some early astronomers（天文学家）believed the sky was a crystal shell or
series of crystal shells,one inside the other. They believed this because that is what the
night sky looked like.For many centuries,men believed that the earth was the center of
the universe and that the sun,the moon,and the stars circled around it.

Early astronomers believed that the sky was a crystal shell or series of crystal shells because_________.
A:he did not observe the sun carefully enough
B:he could not see its curve
C:the sun,the moon and the stars seemed to move around it
D:the earth circles around the sun
E:it looked like that at night
F:it has power over life on earth

Passage 2
If the population of the earth goes on increasing at its present rate, there will eventually not be enough resources left to sustain life on the planet. By the middle of the 21st century, if present trends continue, we will have used up all the oil that drives our cars, for example. Even if scientists develop new ways of feeding the human race, the crowded conditions on earth will make it necessary for us to look for open space somewhere else. But none of the other planets in our solar system are capable of supporting life at present. One possible solution to the problem, however, has recently been suggested by an American scientist, Professor Carl Sagan.
Sagan believes that before the earth's resources are completely exhausted it will be possible to change the atmosphere of Venus and so create a new world almost as large as earth itself. The difficulty is that Venus is much hotter than the earth and there is only a tiny amount of water there.
Sagan proposes that algae organisms, which can live in extremely hot or cold atmospheres and at the same time produce oxygen, should be bred in conditions similar to those on Venus. As soon as this has been done, the algae will be placed in small rockets. Spaceships will then fly to Venus and fire the rockets into the atmosphere. In a fairly short time, the algae will break down the carbon dioxide into oxygen and carbon.
When the algae have done their work, the atmosphere will become cooler, but before man can set foot on Venus it will be necessary for the oxygen to produce rain. The surface of the planet will still be too hot for men to land on it but the rain will eventually fall and in a few years something like earth will be reproduced on Venus.
Man can eventually land on Venus only when__________.

A. the algae have done their work
B. the atmosphere becomes cooler
C. there is oxygen
D. it rains there

共用题干
第三篇

Preserve the Environment

Throughout history man has changed his physical environment in order to improve his way of life.
With the tools of technology he has altered many physical features of the earth.He has transformed
woodlands into farmland,and made lakes and reservoirs out of rivers for irrigation purposes or hydroelectric
power. Man has also modified the face of the earth by draining marshes and cutting through mountains to
build roads and railways.
However,man's changes to the physical environment have not always had beneficial results.Today,
pollution of the air and water is an increasing danger to the health of the planet.Each day thousands of tons
of gases come out of the exhausts of motor vehicles;smoke from factories pollutes the air of industrialized areas
and the surrounding areas of countryside.The air in cities is becoming increasingly unhealthy.
The pollution of water is equally harmful.In the sea,pollution from oil is increasing and is killing enor-
mous numbers of algae（水藻）,fish and birds.The whole ecological balance of the sea is being changed.
The same problem exists in rivers.Industrial wastes have already made many rivers lifeless.
Conservationists believe that it is now necessary for man to limit the growth of technology in order to sur-
vive on earth.

Man has changed his physical environment with a view to_________.
A:altering the physical features of the earth
B:modifying the face of the planet
C:improving his surroundings'
D:bettering his way of life

共用题干
The world has got rainforests which cover 7% of the earth's surface.They grow around the earth's equator in South America,Central America,Africa,Southeast Asia,and Australia. Rainforests are important.(46)______.These rainforests are wet and warm.They get more than two meters of rain each year,and temperatures are usually between 24℃and 27℃．(47)______. Each area has a different environment with different plants,trees and animals.
(48)______.Every day a part of the rainforest,the same size as a football field,is destroyed because of human activities.(49)______,people cut down trees to make plantations to grow food,to get minerals or metals out of the ground or to build more and more houses.(50) ______.Cutting down trees must be prohibited and wild animals must be protected.If people break these rules,they must be arrested and severely punished.

_________（47）
A:Therefore strict measures must be taken
B:They give the earth oxygen,and are the home for half of the world's animals and plants
C:Because of a growing population
D:Unfortunately,these rainforests are in danger
E:Tropical rainforests are home to tribal peoples who rely on their surroundings for food,shelter,and medicines
F: They are divided into four different areas

共用题干
To Survive or to Vanish

1.Over 3.6 billion years ago,the first creature was born in the world.Since then,the earth started its era with life.The history of life on earth has been a history of interaction between living things and their surroundings.To a large extent,the physical form and the habits of the earth's vegetation and its animal life have been molded by the environment. Considering the whole span of earthly time,the opposite effect,in which life actually modifies its surroundings,has been relatively slight. Only in the present century has one species一man acquired significant power to alter the nature of his world.
2.During the past 25 years,this power has not only become increasingly great but it has changed in character. The most alarming of all man's assaults upon the environment is the contamination of air,earth,rivers,and sea with dangerous and even lethal materials. This pollution is for the most part irrecoverable.In this now universal contamination of the environment,chemicals are the sinister partners of radiation in changing the very nature of the world the very nature of its life. Chemicals sprayed on croplands or forests or gardens lie long in soil,entering into living organisms, passing from one to another in a chain of poisoning and death.Or they pass mysteriously by underground streams until they emerge and combine into new forms that kill vegetation,sicken cattle,and work unknown harm on those who drink from once pure wells."Man can hardly even recognize the devils of his own creation,"as a scientist has said.
3.Hundreds of millions of years have passed before the globe produced the life that now inhabits the earth.Given time not in years but in millennia life adjusts,and a balance has been reached.But in the modern world there is no time.
4.The quick steps of change follows the impetuous pace of man rather than the deliberate pace of nature.Radiation is now the unnatural creation of man's tampering with the atom.The chemicals are the synthetic creations of man's inventive mind,having no counterparts in nature.
5.To survive these chemicals would require not merely the years of one man's life but the life of generations.And even this,were it by some miracle possible,would be futile,for the new chemicals come from our laboratories in an endless stream;almost five hundred annually find their way into actual use in the United States alone.Among them are many that are used in man's war against nature.Since the mid l940's over 200 basic chemicals have been created for use in killing insects,weeds,and other organisms described as"pests".
6.It is not my contention that chemical insecticides must never he used.I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm. We have subjected enormous numbers of people to contact with these poisons,without their consent and often without their knowledge.I contend,furthermore,that we have allowed these chemicals to be used with little or no advance investigation of their effect on soil,water,wildlife,and man himself. Future generations are unlikely to forgive our lack of concern for the integrity of the natural world that supports all life.

The effect of life modifying its surroundings has been_______.
A:man's tampering with the atom
B:enormous numbers of people to contact with these poisons
C:the integrity of the natural world that supports all life
D:inventive
E:irrecoverable
F:relatively slight

Each man and woman must sign ______ full names before entering the examination room.

A.his

B.her
C.their

D.one’s

共用题干
Early Ideas about the Universe

1 Early man got his ideas about the universe by looking at the stars as you do.He
observed carefully,and learned many things about the sun,the moon,and the stars.
2 Suppose you were asked to collect evidence about the sun as early man did.You might
go out morning after morning and see it come up in the east.Even on cloudy mornings,you
would observe that the darkness goes away and the world becomes light.You might not see
the sun but would be sure it is there,because you notice that the earth warms up.As you
continued,the sun climbs higher in the sky each day during part of the year. It stays in the
sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.
3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin
to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell
exactly why it happens.But you realize that the sun seems to make the difference.
Primitive（原始的）man felt that since the sun was so powerful it must be a god. It may
seem silly to us now to worship（崇拜）a sun-god, but primitive man was right about the
importance of the sun to life on earth.
4 You have been told that the world is round.But suppose no one had ever taught you
that the world was like a huge ball.Would you have ever thought of it yourself?You cannot
see the curve（曲线）of the earth at once. You would have no idea of how big it was.
That's why early man believed that the earth was small and flat.Such ideas appeared from
the evidence they had.
5 If you watch the stars night after night,you will see them rise and set.As you look at
the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling
（闪烁）lights. Some early astronomers（天文学家）believed the sky was a crystal shell or
series of crystal shells,one inside the other. They believed this because that is what the
night sky looked like.For many centuries,men believed that the earth was the center of
the universe and that the sun,the moon,and the stars circled around it.

Primitive man believed the sun was a god because_________.
A:he did not observe the sun carefully enough
B:he could not see its curve
C:the sun,the moon and the stars seemed to move around it
D:the earth circles around the sun
E:it looked like that at night
F:it has power over life on earth