When Christmas time is upon us, there won't be many families without some type of Christmas tree. Most will choose between a cut pine tree and an artificial plastic tree.

Artificial Christmas trees are usually made from steel and the plastic known as PVC. To produce one kilogram of raw PVC you need over a kilo of fossil fuels plus half a kilo of minerals and 10 L of water. The process also releases about two kilograms of CO₂ ― which contributes to climate change ― and eight grams of dangerous waste.

Most live Christmas trees come either from small plantations dedicated to growing trees just for Christmas or are the rejects from large pine plantations. In both cases, the growing trees provide some long-term soil protection and suck up climate-change-causing carbon dioxide from the atmosphere. However, the use of fertilizers and pollution from machinery can have negative impacts on the local ecosystems.

Both types of trees require transportation to reach your home, which means fuels are burnt and air pollution generated. The greater the distance travelled, the larger the impact, and plastic trees certainly rack up the kilometres. The vast majority of Australia’s artificial trees are made in factories in Asia. If a family in Melbourne buys a plastic tree made in China, then it has travelled more than 8,000 km to arrive at its new home. Alternatively, someone living near Melbourne's CBD could get a real tree from a plantation less than 50 km away.

Despite the shorter life span, real trees are the way to go, because a natural tree can be reused in its afterlife. A plastic Christmas tree can’t be recycled and that means its final resting place will be the local dump. Here the PVC will stay in much the same form for thousands of years.

72. Which of the following is NOT TRUE according to the passage?

      A. Artificial Christmas trees are usually made from steel and plastic.

B. The process of producing PVC does great harm to the environment.

C. Real Christmas trees usually come from large or small plantations.

D. Real Christmas trees release much carbon dioxide while growing.

73. By saying “rack up the kilometres”, the author probably means that the transportation of plastic trees _______.

A. is more convenient                         B. produces more pollution

C. covers a shorter distance                D. can save more fuels

74. According to the passage, real Christmas trees _______ compared with fake ones.

A. use fewer resources                       B. are more difficult to recycle

C. last much longer                             D. are less expensive

75. Which of the following is the most suitable title for this passage?

A. Real Christmas Trees: A Wasteful luxury

B. Fake Christmas Trees: A Economical Choice

C. Real Christmas Trees: A Greener Decision

D. Fake Christmas Trees: A Popular Trend

A green house is a building made of glass which is used for keeping warm when the outside temperature is low. In a similar way there are several gases in the atmosphere (mixture of gases that surround the earth) which trap the heat produced by the sun and prevent it from escaping. These gases are known as “greenhouse gases”. and the way in which they trap heat in the atmosphere is called the “greenhouse effect”. This is not simply air pollution. Most of the main greenhouse gases exist naturally in small amounts in our atmosphere, and without them the earth would be 30 degrees colder and human life would not exist. In other words, the greenhouse effect is a natural course which is to some degree helpful to us.

The problem is that in the last century and a half, we have been putting too many of these gases into the earth’s atmosphere by burning large quantities of coal and oil and by cutting down forest. The rapid increase in greenhouse gases is making the world warmer. The world’s temperature has already gone up by half a degree this century, and the sea level has risen by 10 centimetres. If the amount of carbon dioxide in the atmosphere doubles, there will probably be a rise in the earth’s temperature of between I and 4℃;. This may seem a small increase, but it would be enough to cause major changes in geography and agriculture. Large areas of the world would be flooded, and some areas would become dry and unable to produce crops. It is important, too, to consider that there may be a delay of about 30 years in the greenhouse effect. This means that we are probably experiencing only now the effect of the gases put into the atmosphere before the 1960s. Since then, our use of these gases has greatly increased.

1. According to the passage, we can know “greenhouse effect” means_______.  

A. the way in which gases are used for keeping plants warm

B. a natural course that is to a certain degree useful to us

C. the way “greenhouse gases” trap heat on the earth

D. the whole course in which greenhouse gases prevent heat

2. If there were no greenhouse effect,_______.

A. all plants would not grow on our planet        B. soil would reduce the temperature by 30 degrees

C. man would breathe the cleaner air              D. people couldn’t live in the earth

3. Which of the following is not true?

A. Burning too much coal and oil produces lots of greenhouse gases.

B. It has become warm on the earth now than in the past.

C. Gases put into the atmosphere now will affect the earth years later.

D. The temperature in a greenhouse is as high as that in the atmosphere.

4. Suppose the earth’s temperature rose by 3 degrees, _______. 

A. great harm will be done to mankind         B. the sea level would go up by 10 centimeters

C. all the land in the world would be flooded     D. crops would be unable to grow on the earth

5. This passage mainly deals with ________.

A. the concept (概念) and the harm of the greenhouse  B. the relation between greenhouse gases and man

C. the concept and change of greenhouse effect            D. the effect of the rise of the earth’s temperature

A green house is a building made of glass which is used for keeping warm when the outside temperature is low. In a similar way there are several gases in the atmosphere (mixture of gases that surround the earth) which trap the heat produced by the sun and prevent it from escaping. These gases are known as “greenhouse gases”. And the way in which they trap heat in the atmosphere is called the “greenhouse effect”. This is not simply air pollution. Most of the main greenhouse gases exist naturally in small amounts in our atmosphere, and without them the earth would be 30 degrees colder and human life would not exist. In other words, the greenhouse effect is a natural course which is to some degree helpful to us.
The problem is that in the last century and a half, we have been putting too many of these gases into the earth’s atmosphere by burning large quantities of coal and oil and by cutting down forest. The rapid increase in greenhouse gases is making the world warmer. The world’s temperature has already gone up by half a degree this century, and the sea level has risen by 10 centimetres. If the amount of carbon dioxide in the atmosphere doubles, there will probably be a rise in the earth’s temperature of between I and 4℃;. This may seem a small increase, but it would be enough to cause major changes in geography and agriculture. Large areas of the world would be flooded, and some areas would become dry and unable to produce crops. It is important, too, to consider that there may be a delay of about 30 years in the greenhouse effect. This means that we are probably experiencing only now the effect of the gases put into the atmosphere before the 1960s. Since then, our use of these gases has greatly increased.

1. 1.

   According to the passage, we can know “greenhouse effect” means_______.  

   1. A.
      the way in which gases are used for keeping plants warm
   2. B.
      a natural course that is to a certain degree useful to us
   3. C.
      the way “greenhouse gases” trap heat on the earth
   4. D.
      the whole course in which greenhouse gases prevent heat
2. 2.

   If there were no greenhouse effect,_______.

   1. A.
      all plants would not grow on our planet
   2. B.
      soil would reduce the temperature by 30 degrees
   3. C.
      man would breathe the cleaner air
   4. D.
      people couldn’t live in the earth
3. 3.

   Which of the following is not true?

   1. A.
      Burning too much coal and oil produces lots of greenhouse gases.
   2. B.
      It has become warm on the earth now than in the past.
   3. C.
      Gases put into the atmosphere now will affect the earth years later.
   4. D.
      The temperature in a greenhouse is as high as that in the atmosphere.
4. 4.

   Suppose the earth’s temperature rose by 3 degrees, _______. 

   1. A.
      great harm will be done to mankind
   2. B.
      the sea level would go up by 10 centimeters
   3. C.
      all the land in the world would be flooded
   4. D.
      crops would be unable to grow on the earth
5. 5.

   This passage mainly deals with ________.

   1. A.
      the concept (概念) and the harm of the greenhouse
   2. B.
      the relation between greenhouse gases and man
   3. C.
      the concept and change of greenhouse effect
   4. D.
      the effect of the rise of the earth’s temperature

阅读理解

　　A greenhouse is a building made of glass which is used for keeping plants warm when the outside temperature is low. In a similar way there are several gasses in the atmosphere which trap(捕捉) the heat produced by the sun and prevent it from escaping. These gasses are known as “greenhouse gasses”, and the way in which they trap heat in the atmosphere is called the “greenhouse effect”. This is not simply air pollution. Most of the main greenhouse gasses exist naturally in small amounts in our atmosphere, and without them earth would be 30 degrees colder and human life would not exist. In other words, the greenhouse effect is a natural course which is to some degree helpful to us.

　　The problem is that in the last century and a half, we have been putting too much of these gasses into the earth's atmosphere by burning large quantities of coal and oil and by cutting down forests. The rapid increase in greenhouse gasses is making the world warmer. The world's temperature has already gone up by half a degree this century, and the sea level has risen by 10 centimetres. If the amount of carbon dioxide in the atmosphere doubles, there will probably be a rise in the earth's temperature between 1 and 4. This may seem a small increase, but it would be enough to cause major changes in geography and agriculture. Large areas of the world would be flooded, and some areas would become dry and unable to produce crops：It is important, too, to consider that there may be a delay of about 30 years in the greenhouse effect. This means that we are probably experiencing only now the effect of the gasses put into the atmosphere before 1960s. Since then, our use of these gasses has greatly increased.

1．“Greenhouse effect” means ________.

[　　]

A．the way in which gasses are used for keeping plants warm

B．a natural course which is to some degree helpful to us

C．the way “greenhouse gasses” trap heat on the earth

D．the whole course in which greenhouse gasses prevent heat

2．If there were no greenhouse effect, ________.

[　　]

A．no plants would grow on our planet

B．earth would be thirty degrees colder

C．man could not live on the earth

D．all of the above answers are correct

3．Which of the following is not among the results of our putting too many of the greenhouse gasses into the air?

[　　]

A．The earth's temperature will rise.

B．The earth's temperature will be much lower.

C．The sea level will rise.

D．Large areas of land will be flooded.

4．Which of the following is not true?

[　　]

A．Burning too much coal and oil produces lots of greenhouse gasses.

B．It has become warmer on the earth now than in the past.

C．Gasses put into the atmosphere now will effect the earth years later.

D．The temperature in a greenhouse is as high as that in the atmosphere.

5．This passage mainly deals with ________.

[　　]

A．the concept and harm of greenhouse effect

B．the relation between greenhouse gasses and man

C．the concept and change of greenhouse effect

D．the effect of the rise of the earth's temperature