Hundreds of years ago, life was much harder than it is today, people did not have modern machines. There was no modern medicine, either.
Life today has brought new problems. One of the biggest is pollution. Water pollution has made our rivers and lakes dirty. It kills our fish and affects our drinking water. Noise pollution makes us talk louder and become angry more easily. Air pollution is the most serious kind of pollution. It affects every living thing in the world.
Cars, planes and factories all pollute our air every day. Sometimes the pollution is so thick that it is like a quilt(被子) over a city. This kind of quilt is called smog.
Many countries are making new laws to fight pollution. Factories must now clean their water before it is thrown away; they mustn’t blow dirty smoke into the air.
We need to do many other things. We can put waste things in the dustbin and not throw them on the ground. We can go to work by bus or with our friends in the some car. If there are fewer people driving, there will be less pollution.
Laws are not enough. Every person must help to fight pollution.
49. Life was harder hundreds of years ago because____________.
A. the weather was bad             B. there were no cities
C. people had no modern machines    D. people couldn’t make machines  
50._______ makes the rivers and lakes dirty.
A Swimming.   B Polluted water   C. Growing population   D. Warmer weather
51.More and more people become angry easily because __________.
A. they can’t get enough money           B. They are often hungry
C. there’s much traffic on the roads        D. there’s much noise around them
52 The writer of the passage thinks__________.
A. everyone should do something to fight pollution
B. all the laws can stop factories going on polluting
C few countries can stop the air and water being polluting
D. people have to live in the polluted air..

Hundreds of years ago, life was much harder than it is today, people did not have modern machines. There was no modern medicine, either.

Life today has brought new problems. One of the biggest is pollution. Water pollution has made our rivers and lakes dirty. It kills our fish and affects our drinking water. Noise pollution makes us talk louder and become angry more easily. Air pollution is the most serious kind of pollution. It affects every living thing in the world.

    Cars, planes and factories all pollute our air every day. Sometimes the pollution is so thick that it is like a quilt(被子) over a city. This kind of quilt is called smog.

Many countries are making new laws to fight pollution. Factories must now clean their water before it is thrown away; they mustn’t blow dirty smoke into the air.

We need to do many other things. We can put waste things in the dustbin and not throw them on the ground. We can go to work by bus or with our friends in the some car. If there are fewer people driving, there will be less pollution.

Laws are not enough. Every person must help to fight pollution.

49. Life was harder hundreds of years ago because____________.

   A. the weather was bad             B. there were no cities

   C. people had no modern machines    D. people couldn’t make machines  

50._______ makes the rivers and lakes dirty.

A Swimming.   B Polluted water   C. Growing population   D. Warmer weather

51.More and more people become angry easily because __________.

   A. they can’t get enough money           B. They are often hungry

   C. there’s much traffic on the roads        D. there’s much noise around them

52 The writer of the passage thinks__________.

   A. everyone should do something to fight pollution

   B. all the laws can stop factories going on polluting

   C few countries can stop the air and water being polluting

   D. people have to live in the polluted air..

　　Every thing living on earth--each plant and animal--needs other living things. Nothing lives alone. Most animals must live in a group, and even a tree or a plant grows close together with others of the same kind. Sometimes one living thing hunts another, one eats and the other is eaten. Each kind of life eats another kind of life in order to live, and together they form a food chain. Some food chains are simple, others are complicated. But all have. two things in common--all food chains began with the sun, and all food chains become broken up if one of the links disappears.

　　All life depends on energy from sunlight. Only plants can use this energy directly. Their leaves are little factories that use sunlight to make food from water and things in the soil and air.

　　Plants in turn feted all other living things. Animals can only use the sun's energy after it has been changed into food by plants. Some animals feed directly on plants, others eat smaller animals. Meat-eating animals are only eating plants indirectly.

　　What about human beings? We are members of many food chains. We eat wheat, rice, vegetables, fruit and so on. We also eat meat and drink milk. This means the sun's energy passes through plants to animals before it reaches us.

　　Nature is a great thing. Any food chain always produces enough for each of its members if it is left alone. When there isn't enough food for any link in the chain, some of its members die off. So the balance is always kept.

　　But men often break up the food chain and do great harm net only to one plant or animal, but also to all the links in the chain. People make seas and rivers dirty. They destroy whole forests and kill many kinds of wild animals birds. When a river becomes dirty, the fish cannot be eaten. Men eat the fish and get strange diseases. In some places men have no fish to eat any more because the fish have died off. Each form of life is linked to all others. Breaking, the links puts all life in danger.

(1) How does everything living on earth live?

[　　]

A．Each plant can live alone.

B．Each animal can live alone.

C．Everything living on earth cannot live without needing other living things.

D．If living things want to live they must kill each other.

(2) How do all food chains break? All food chains are broken if ________.

[　　]

A．one kind of animal is eaten up

B．one kind of plant is destroyed

C．one kind of animal eats another

D．one of the links is destroyed

(3) How is food for plants made? Food for plants is made ________.

[　　]

A．from water

B．from the air in the sky

C．from the soil

D．from water and things in the soil and air

(4) Which living things can use energy directly?

[　　]

(5) Why is all life in danger? Because ________ break up the food chains.

[　　]

　　Every thing living on earth--each plant and animal--needs other living things. Nothing lives alone. Most animals must live in a group, and even a tree or a plant grows close together with others of the same kind. Sometimes one living thing hunts another, one eats and the other is eaten. Each kind of life eats another kind of life in order to live, and together they form a food chain. Some food chains are simple, others are complicated. But all have. two things in common--all food chains began with the sun, and all food chains become broken up if one of the links disappears.

　　All life depends on energy from sunlight. Only plants can use this energy directly. Their leaves are little factories that use sunlight to make food from water and things in the soil and air.

　　Plants in turn feted all other living things. Animals can only use the sun's energy after it has been changed into food by plants. Some animals feed directly on plants, others eat smaller animals. Meat-eating animals are only eating plants indirectly.

　　What about human beings? We are members of many food chains. We eat wheat, rice, vegetables, fruit and so on. We also eat meat and drink milk. This means the sun's energy passes through plants to animals before it reaches us.

　　Nature is a great thing. Any food chain always produces enough for each of its members if it is left alone. When there isn't enough food for any link in the chain, some of its members die off. So the balance is always kept.

　　But men often break up the food chain and do great harm net only to one plant or animal, but also to all the links in the chain. People make seas and rivers dirty. They destroy whole forests and kill many kinds of wild animals birds. When a river becomes dirty, the fish cannot be eaten. Men eat the fish and get strange diseases. In some places men have no fish to eat any more because the fish have died off. Each form of life is linked to all others. Breaking, the links puts all life in danger.

(1) How does everything living on earth live?

[　　]

A．Each plant can live alone.

B．Each animal can live alone.

C．Everything living on earth cannot live without needing other living things.

D．If living things want to live they must kill each other.

(2) How do all food chains break? All food chains are broken if ________.

[　　]

A．one kind of animal is eaten up

B．one kind of plant is destroyed

C．one kind of animal eats another

D．one of the links is destroyed

(3) How is food for plants made? Food for plants is made ________.

[　　]

A．from water

B．from the air in the sky

C．from the soil

D．from water and things in the soil and air

(4) Which living things can use energy directly?

[　　]

(5) Why is all life in danger? Because ________ break up the food chains.

[　　]

What do you know about the sea? We know that it looks very pretty when the sun is shining on it. We also know that it can be very rough when there is a strong wind. What other things do we know about it?

The first thing to remember is that the sea is very big. When you look at the map of the world you will find there is more water than land. The sea covers three quarters of the world.

The sea is also very deep in some places. It is not deep everywhere. Some parts of the sea are very shallow. But in some places the depth of the sea is very great. There is one spot, near Japan,  where the sea is nearly 11 kilometers deep! The highest mountain in the world is about 9 kilometers high. If that mountain were put into the sea at that place, there would be 2 kilometers of water above it! What a deep place!

If you have swum in the sea, you know that it is salty. You can taste the salt. Rivers, which flow into the sea, carry salt from the land into the sea. Some parts of the sea are saltier than other parts. There is one sea, called the Dead Sea, which is very salty. It is so salty that swimmers cannot sink! Fish cannot live in the Dead Sea!

In most parts of the sea, there are plenty of fish and plants. Some live near the top of the sea. Others live deep down. There are also millions of tiny living things that float in the sea. These floating things are so small that it is hard to see them. Many fish live by eating these floating things.

The sea can be very cold. Divers who go deep down in the sea know this. On the top the water may be warm. When the diver goes downwards, the sea becomes colder and colder. Another thing happens. When the diver goes deeper, the water above presses down on him. It squeezes him. Then the diver has to wear clothes made of metal. But he cannot go very deep. Some people who wanted to go very deep used a very strong diving ship!  They went down to the deepest part of the sea in it. They went down to a depth of eleven kilometers!

66. When does the sea look beautiful?

A. When it is calm.

B. When the weather is fine.

C. When there is a strong wind.

D. When there is a storm.

67. How much of the earth’s surface does land cover?

A. 15%                 B. 25%                  C. 30%                 D. 45%

68. Why does the author mention the sea somewhere near Japan?

A. To show that the sea in some places is very deep.

B. To show that the sea in some places is very shallow.

C. To show that its depth is 9 kilometers greater than the height of the highest mountain.

D. To show that its depth is 11 kilometers greater than the height of the highest mountain.

69. Which of the following statements about the Dead Sea is NOT true?

A. There are plenty of fish in it.

B. It is a safe place for swimmers.

C. It is extremely salty.

D. No fish can be found in it.

70. Why can’t people go very deep in the sea?

A. Because the deepest part of the sea is very cold.

B. Because the deepest part of the sea is very rough.

C. Because the pressure of the water at great depths is unendurable.

D. Because fierce fish usually live there.