—What did the doctor say?   —He asked how long _________.

Carbon monoxide poisoning (一氧化碳中毒) causes death and injuries around the world. This gas is a problem in all parts of the world that experience cold weather. A few years ago, America’s Centers for Disease Control (C. D. C.) studied deaths linked (联系) with carbon monoxide poisoning. It found that the number of carbon monoxide deaths in the United States was greatest in January. The C.D.C. also found that carbon monoxide kills more than four hundred Americans each year. And, it said more than twenty thousand people are taken to hospital for treatment of health problems linked with the gas.

   Carbon monoxide is called the silent killer because people do not know it is in the air. The gas has no color, no taste and no smell. It does not cause burning eyes. And it does not cause people to cough. Yet, carbon monoxide gas is very deadly (致命的). It steals the body’s ability to use oxygen.

Carbon monoxide makes it difficult for the blood to carry oxygen to body tissues (血管). It does this by linking with the blood. When the gas links with the blood, the blood is no longer able to carry oxygen to the tissues that need it. Damage (损害) to the body can begin very quickly from large amounts (数量) of carbon monoxide.

How quickly this can happen depend on how long a person is breathing the gas and how much gas he or she breathes in.

   Carbon monoxide poisoning has warning signs(标志). But people have to be awake to realize them. Small amounts of the gas will cause a person’s head to hurt. He or she may begin to feel tired. Their stomachs may feel sick. The room may appear to be turning around. The person may have trouble thinking clearly.

People develop serious headache as the amount of the gas continues to enter their blood. They will begin to feel very tired and sleepy. They may have terrible stomachache.

Doctors say carbon monoxide influences people differently. For example a small child will experience health problems or die much sooner than an adult. The general health of the person or his or her age can also be important.

1.The damage of carbon monoxide to the body has something to do with _____.

A. the amount a person breathes in         

B. whether a person is healthy

C. how many signs a person finds           

D. ages of people

2.One of the signs of carbon monoxide poisoning is _____.

A. burning eyes                         B. bad cough

C. serious headache                     D. high fever

3.Which of the following is TRUE according to the passage?

A. Carbon monoxide poisoning seldom happens in cold areas.

B. Twenty thousand Americans are killed by carbon monoxide each year.

C. Most people know whether there is carbon monoxide in the air.

D. Carbon monoxide stops the blood from carrying oxygen to body tissues.

4.What does the passage mainly talk about?

A. Warning signs that carbon monoxide poisoning has.

B. Reasons why carbon monoxide can cause person’s death.

C. The damage of carbon monoxide and how it works.

D. Influences of carbon monoxide on children and adults.

—What did the doctor say?   —He asked how long _________.

Carbon monoxide poisoning (一氧化碳中毒) causes death and injuries around the world. This gas is a problem in all parts of the world that experience cold weather. A few years ago, America’s Centers for Disease Control (C. D. C.) studied deaths linked (联系) with carbon monoxide poisoning. It found that the number of carbon monoxide deaths in the United States was greatest in January. The C.D.C. also found that carbon monoxide kills more than four hundred Americans each year. And, it said more than twenty thousand people are taken to hospital for treatment of health problems linked with the gas.
Carbon monoxide is called the silent killer because people do not know it is in the air. The gas has no color, no taste and no smell. It does not cause burning eyes. And it does not cause people to cough. Yet, carbon monoxide gas is very deadly (致命的). It steals the body’s ability to use oxygen.
Carbon monoxide makes it difficult for the blood to carry oxygen to body tissues (血管). It does this by linking with the blood. When the gas links with the blood, the blood is no longer able to carry oxygen to the tissues that need it. Damage (损害) to the body can begin very quickly from large amounts (数量) of carbon monoxide.
How quickly this can happen depend on how long a person is breathing the gas and how much gas he or she breathes in.
Carbon monoxide poisoning has warning signs(标志). But people have to be awake to realize them. Small amounts of the gas will cause a person’s head to hurt. He or she may begin to feel tired. Their stomachs may feel sick. The room may appear to be turning around. The person may have trouble thinking clearly.
People develop serious headache as the amount of the gas continues to enter their blood. They will begin to feel very tired and sleepy. They may have terrible stomachache.
Doctors say carbon monoxide influences people differently. For example a small child will experience health problems or die much sooner than an adult. The general health of the person or his or her age can also be important.
【小题1】The damage of carbon monoxide to the body has something to do with _____.