阅读下面短文，根据所读内容在文后小题的空格里填上适当的单词或短语。注意：每空不超过3个单词。
Each year there is an increasing number of cars as millions of new cars are produced in America. Americans will not live without cars! However, some have realized the serious problem of air pollution by cars. It is necessary to find ways to solve the problem of air pollution.
One way to clean the air is to build a new kind of clean car. That’s what several of the large car factories are trying to do. But to build a clean car is easier said than done. Progress in this field has been slow.
Another way is to take the place of the car engine by something else. Engineers are now working on it. Many makers believe that it will take years to develop a practical model for us.
To prevent the world being polluted by cars, Americans have to make some changes in the way of their life. They have to cut down on the number of their cars and are encouraged to travel and go to work by bike. But this change does not come easily. Many workers may find themselves without jobs if a car factory closes down. And the problem of their pollution would become less important than that of unemployment.
Americans may live a happy but sad life for a long time because of the car problem.
Cars and Pollution in American

请认真阅读下列短文，并根据所读内容在文章表格中的空格里填入一个最恰当的单词。注意：每个空格只填一个单词。请将答案写在答题卡上相应的横线上。

Each year there is an increasing number of cars as millions of new cars are produced in America . Americans will not live without cars ! However , some have realised the serious problem of air pollution by cars . It is necessary to find ways to solve the problem of air pollution .

One way to clean the air is to build a new kind of clean car . That’s what several of the large car factories are trying to do . But to build a clean car is easier said than done . Progress in this field has been slow .

Another way is to take the place of the car engine by something else . Engineers are now working on it . Many makers believe that it will take years to develop a practical model that can please man .

To prevebt the world being polluted by cars , They have to cut down on the number of their cars and are encouraged to travel and go to work by bike . But this change doesn’t close down ---- many workers may find themselves without jobs if a car factory closes down . And the problem of their pollution would become less important than that of unemployment.

Title : (1) _____ and Pollution in America

Each year there is an increasing number of cars on roads and streets as millions of new cars and trucks are produced. One out of every six Americans works at putting together the parts of cars, driving trucks, building roads or filling cars and trucks with gas.  

Most Americans would find it hard to imagine what life would look like without cars.  . The polluted air becomes poisonous and dangerous to health.

  . That’s what several of the large car factories have been trying to do. But to build a clean car is easier said than done. Progress in this field has been slow.

Another way is to take the place of the car engine by something else.   . Many makers believe that it will take years to develop a practical model that pleases man.

To prevent the world from being polluted by cars, we’ll have to make some changes in the way many of us live. Americans, for example, have to cut down on the number of their total cars. They are encouraged to travel and go to work by bicycle. Bicycling is thought to help the air clean. But this change does not come easily. A large number of workers may find themselves without jobs if a car factory closes down.  .

Although cars have led us to a better life, they have also brought us new problems.

A.Thus the problem of air pollution would become less important than that of unemployment.

B. Americans know cars very well.

C. However, some have realized the serious problems of the air pollution that is caused by cars.

D. One way to get rid of the polluted air is to build a car that does not pollute.

E. However, the number of vehicles has continued to increase in recent years.

F. Americans won’t live without cars!

G. Inventors are now working on steam cars as well as electric cars.

The effects of air pollution on natural conditions have been a disturbing problem for many years. Some scientists hold the view that the air inside houses may be more dangerous than the air outside. It may even be one hundred times worse.

Most scientists agree that every modern house has some kind of indoor pollution, which can cause a person to feel tired, to suffer eye pain, headache and other problems. Believe it or not, some pollutants can cause breathing diseases of blood and even cancer.

What made us feel relieved is that there’s growing concern about the problem now. It is true that when builders began constructing houses and offices they did not want to waste energy. To do this they built buildings that prevented or limited the flow of air between inside and outside. For the same purpose, man-made building materials were employed to build houses, which are now known to let out some harmful gases.

Facing the serious challenge, scientists have been searching for a way to handle the problem. To everyone’s delight, they discovered a natural pollution control system for building—green plants, though they do not really know how plants control air pollution. Scientists suppose that a plant’s leaves absorb or take in the pollutants and in exchange gives out oxygen through its leaves and tiny organizations on its roots. Therefore they recommend that all buildings should have one large plant or several small plants inside for every nine square meters of space. Because studies indicate that different plants absorb different chemicals, the most effective way to clean the air is to use different kinds of plants. In conclusion, having green plants inside your house can make it a prettier and healthier place. Why not try?

1.Which of the following statements is TRUR?

2.According to scientists, some kind of indoor pollution can be found in ________.

3.What does the underlined part “To do this” refer to in Para3?

4.The reason why we should use different kinds of plants to clean the air is that ___.

For years scientists have been concerned about the effects of air pollution on the earth's natural conditions. Some believe the air inside many houses may be more dangerous than the air outside. It may be one hundred times worse.

Indoor air pollution can cause a person to feel tired,to suffer eye pain, headache and other problems.Some pollutants(污染物)can cause breathing disorders,diseases of blood and even cancer. Most scientists agree that every modern house has some kind of indoor pollution.People began to notice the problem in the early 1970s.It is said that when builders began making houses and offices they did not want to waste energy.To do this,they built buildings that limited the flow of air between inside and outside.They also began using man-made building materials.These materials are now known to let out harmful gases.As the problem became more serious, scientists began searching for a way to deal with it.They discovered a natural pollution control system for building－green plants.Scientists do not really know how plants control air pollution.They believe that a plant's leaves absorb or take in the pollutants.In exchange the plant lets out oxygen through its leaves and through its tiny organizations on its roots.Scientists suggest that all buildings should have one large plant or several small plants inside for every nine square metres of space.Studies of different plants show that each absorbs different chemicals.So the most effective way to clean the air is to use different kinds of plants.Having green plants inside your house can make it a prettier and healthier place.

77.What is the topic of the passage?

A.Air pollution.           

B.Green plants indoors.

C.Indoor air pollution.         

D.Environment protecting.

78.What makes indoor air pollution more harmful than that of the air outside?

A.The limited flow of air indoors.

B.Man-made building materials.

C.Fewer green plants inside houses.     

D.The energy-saving materials indoors.

79.The most effective way to clean the air is to use different kinds of plants because______.

A.they can make houses pettier and healthier

B.they may let out oxygen which people need

C.they can take in all kinds of indoor pollutants  

D.they can absorb different harmful indoor chemicals

80.Which of the following is implied but NOT stated?

A.keep windows open and let fresh air in.

B.Scientists have a clear idea how plants control air pollution.

C.Oxygen is let out through the leaves and roots of the plants.

D.Green plants are a natural pollution control system for building.