To extinguish (熄灭) different kinds of fires, several types of fire extinguishers have been invented. They must be ready for immediate use when fire breaks out. Most portable (手提式的) kinds operate for less than a minute, so they are useful only on small fires. The law requires ships, trains, buses and planes to carry extinguishers.

Since fuel, oxygen (氧气) and heat must be present in order for fire to exist, one or more of these things must be removed or reduced to extinguish a fire. If the heat is reduced by cooling the material below a certain temperature, the fire goes out. The cooling method is the most common way to put out a fire. Water is the best cooling material because it is low in cost and easy to get.

Another method of extinguishing fire is by cutting off the oxygen. This is usually done by covering the fire with sand, steam or some other things. A blanket may be used do cover a small fire.

A third method is called separation, which includes removing the fuel, or material easy to burn, from a fire, so that it can find no fuel.

The method that is used to put out a fire depends upon the type of fire. Fires have been grouped in three classes. Fires in wood, paper, cloth and the like are called Class A fires. These materials usually help keep the fire on. Such fires can be stopped most readily by cooling with water.

1.If a fire breaks out on a bus, which of the follow should be ready there for you to use?

A. Sand                             B. Water

C. A blanket.                           D. An extinguisher.

2.To cover a small piece of burning wood with a basin in order to stop the fire is an example of         .

A. separating the fire                  B. reducing the heat

C. removing the fuel                    D. cutting off the oxygen

3.In choosing how to put out a fire, we should first be clear about          .

A. when it breaks out                   B. how it comes about

C. what kind it is                      D. where it takes place

4.What would the author probably discuss in the paragraph that follows?

A. Another class of fires                   B. Another type of extinguishers

C. How fires break out.                 D. How fires can be prevented.

     The scene in the Hollywood movie The Day After Tomorrow, where global warming could soon turn the global climate (气候) into a new ice age, may never occur, according to new research.

    The next ice age could be 15,000 years away, say European scientists who last month announced a continuous record of 7.40,000 years of climate data (数据) obtained from the Antarctic ice.                         

     Scientists from 10 nations have now almost completely drilled through a 3,000-meter.depth of ice high in the Antarctic mainland. They figure out that the area where summer temperatures can fall to –40℃, has at least 900,000 years of snowfalls,, kept as neatly as the growth rings of a tree. And the ice and air caught in each layer(层) have begun to answer questions about the climates in the past..

     The results show that there have been eight ice ages in the past 740, 000 years and eight warmer periods. And by comparing the pattern of global conditions today with those of the past, the researchers reported in Nature that the present warm period could last another 15, 000 years.

     Research suggests that there is a very close connection between greenhouse gas levels and global average temperatures. It also shows that carbon dioxide (二氧化碳) levels are the highest for at least 440,000 years.         

     "If people say to you: the greenhouse effect is a good thing because we would go into an ice age otherwise, our data say no, a new ice age is not hanging over our heads,” said Eric Wolff from the British Antarctic Survey. "Now we have eight examples of how the climate goes in and out of ice ages… and you can learn what the rules are that go into the climate models that tell us about the future."

     Scientists found that whenever temperatures rose in the frozen record, so did carbon dioxide level. "In 440,000 years we have never seen greenhouse gas get as thick as it is today," said Dr Wolff.

48. In drilling through the ice in Antarctica, scientists, have found that______.

     A. the lowest temperature there is －40℃     B. the depth of ice is 3,000 meters

     C. the ice has existed for 15,000 years          D. snowfalls are kept in certain patterns

49. The information of the global climate conditions in the past can be obtained through______.

     A. separating carbon dioxide from the air     

   B. examining the growth rings of trees

     C. comparing temperatures in different areas

     D. studying the ice and air caught in each layer

50. We can infer from Eric Wolff's words that_______.

     A. there is something wrong with the data     B. greenhouse effect is always a bad thing

     C. a new ice age will not come in the near future

     D. greenhouse gas will get thick in the future

51. What would be the best title for the passage?

     A. Research over the Antarctic area.                    B. Warm period to last about 15, 000 years.

     C. Report on the eight ice ages in the past.    D. Hollywood movies and the global climate.

   To extinguish (熄灭) different kinds of fires, several types of fire extinguishers have been invented. They must be ready for immediate use when fire breaks out. Most portable (手提式的) kinds operate for less than a minute, so they are useful only on small fires. The law requires ships, trains, buses and planes to carry extinguishers.

    Since fuel, oxygen (氧气) and heat must be present in order for fire to exist, one or more of these things must be removed or reduced to extinguish a fire. If the heat is reduced by cooling the material below a certain temperature, the fire goes out. The cooling method is the most common way to put out a fire. Water is the best cooling material because it is low in cost and easy to get.

    Another method of extinguishing fire is by cutting off the oxygen. This is usually done by covering the fire with sand, steam or some other things. A blanket may be used do cover a small fire.

    A third method is called separation, which includes removing the fuel, or material easy to burn, from a fire, so that it can find no fuel.

    The method that is used to put out a fire depends upon the type of fire. Fires have been grouped in three classes. Fires in wood, paper, cloth and the like are called Class A fires. These materials usually help keep the fire on. Such fires can be stopped most readily by cooling with water.

68. If a fire breaks out on a bus, which of the follow should be ready there for you to use?

A. Sand           B. Water         C. A blanket.           D. An extinguisher.

69. To cover a small piece of burning wood with a basin in order to stop the fire is an example of         .

A. separating the fire                                 B. reducing the heat

C. removing the fuel                                 D. cutting off the oxygen

70. In choosing how to put out a fire, we should first be clear about          .

A. when it breaks out                                B. how it comes about

C. what kind it is                                       D. where it takes place

71. What would the author probably discuss in the paragraph that follows?

A. Another class of fires                                   B. Another type of extinguishers

C. How fires break out.                                 D. How fires can be prevented.

 To extinguish （熄灭）different kinds of fires, several types of fire extinguishers have been invented. They must be ready for immediate use when fire breaks out. Most portable （手提式的）kinds operate for less than a minute, so they are useful only on small fires. The law requires ships, trains, buses and planes to carry extinguishers.

 Since fuel（燃料）, oxygen and heat must be present in order for fire to exist, one or more of these things must be removed or reduced to extinguish a fire. If the heat is reduced by cooling the material below a certain temperature, the fire goes out. The cooling method is the most common way to put out a fire. Water is the best cooling material because it is low in cost and easy to get.

 Another method of extinguishing fire is by cutting off the oxygen. This is usually done by covering the fire with sand, steam or some other things. A blanket may be used do cover a small fire.

 A third method is called separation, which includes removing the fuel, or material easy to burn, from a fire, so that it can find no fuel.

 The method that is used to put out a fire depends on the type of fire. Fires have been grouped in three classes（级别）. Fires in wood, paper, cloth and the like are called Class A fires. These materials usually help keep the fire on. Such fires can be stopped most readily by cooling with water.

If a fire breaks out on a bus, which of the following should be ready there for you to use?

 A. Sand                 B. An extinguisher      C. A blanket.           D. Water

To cover a small piece of burning wood with a basin in order to stop the fire is an example of _______.

 A. separating the fire                             B. cutting off the oxygen

 C. removing the fuel                               D. reducing the heat

In choosing how to put out a fire, we should first be clear about_______.

 A. when it breaks out                 B. how it comes about

 C. what kind it is                      D. where it takes place

What would the author probably discuss in the paragraph that follows?

 A. Another class of fires                       B. Another type of extinguishers

 C. How fires break out.                        D. How fires can be prevented.

  To extinguish （熄灭）different kinds of fires, several types of fire extinguishers have been invented. They must be ready for immediate use when fire breaks out. Most portable （手提式的）kinds operate for less than a minute, so they are useful only on small fires. The law requires ships, trains, buses and planes to carry extinguishers.

 Since fuel（燃料）, oxygen and heat must be present in order for fire to exist, one or more of these things must be removed or reduced to extinguish a fire. If the heat is reduced by cooling the material below a certain temperature, the fire goes out. The cooling method is the most common way to put out a fire. Water is the best cooling material because it is low in cost and easy to get.

 Another method of extinguishing fire is by cutting off the oxygen. This is usually done by covering the fire with sand, steam or some other things. A blanket may be used do cover a small fire.

 A third method is called separation, which includes removing the fuel, or material easy to burn, from a fire, so that it can find no fuel.

 The method that is used to put out a fire depends on the type of fire. Fires have been grouped in three classes（级别）. Fires in wood, paper, cloth and the like are called Class A fires. These materials usually help keep the fire on. Such fires can be stopped most readily by cooling with water.

1.If a fire breaks out on a bus, which of the following should be ready there for you to use?

 A. Sand                 B. An extinguisher      C. A blanket.           D. Water

2.To cover a small piece of burning wood with a basin in order to stop the fire is an example of _______.

 A. separating the fire                             B. cutting off the oxygen

 C. removing the fuel                               D. reducing the heat

3.In choosing how to put out a fire, we should first be clear about_______.

 A. when it breaks out                 B. how it comes about

 C. what kind it is                      D. where it takes place

4.What would the author probably discuss in the paragraph that follows?

 A. Another class of fires                       B. Another type of extinguishers

 C. How fires break out.                        D. How fires can be prevented.