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 to carbon monoxide poisoning. It found that the average 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 emergency rooms for treatment of health problems linked to 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. It steals the body's ability to use oxygen.
     Carbon monoxide decreases the ability of the blood to carry oxygen to body tissues. It does this by linking
with the blood. When the gas links with the blood, the blood is no longer 1able to carry oxygen to the tissues
that need it. Damage to the body can begin very quickly from large amounts of carbon monoxide.
     How quickly this can happen depends on the length of time a person is breathing the gas and the amount of
the gas he or she breathes in.
     Carbon monoxide poisoning has warning signs. But people have to be awake to recognize them. Small
amounts of the gas will cause a person's head to hurt. He or she may begin to feel tired. The victim's stomach
may feel sick. The room may appear to be turning around. The person may have trouble thinking clearly.
     People develop severe head pain as the amount of the gas continues to enter their blood. They will begin to
feel very tired and sleepy. They may have terrible stomach pains.
     Medical experts say carbon monoxide affects 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. What can we learn from the last paragraph?

A. A small child will experience health problems or die much slower than an adult.
B. An unhealthy adult may suffer more from the effects of CO than normal people.
C. People with heart disease do not suffer chest pains.
D. Carbon monoxide affects people all the same.

2. What is the most deadly damage to one's life when CO is breathed in?

A. It stops the blood from carrying oxygen to where the body needs.
B. It may cause him/her to feel tired and sleepy.
C. It often causes him/her to suffer terrible stomachache.
D. It slows down people's thinking.

3. The damage of CO to the body has something to do with _____.

A. people's gas intake
B. people's length
C. people's reaction
D. whether people are sleeping or not

     Carbon monoxide(一氧化碳) poisoning kills and injures many people and animals around
the world. The gas has been a problem since people first began burning fuels to cook food or to
create heat. It is a problem in all parts of the world that experience cold weather.
     Carbon monoxide is called the silent killer because people do not know it is in the air. The gas
has no color. It has no taste. It has no smell. It does not cause burning eyes. And it does not cause
people to cough. But it is very deadly. It robs the body of its ability to use oxygen.
     Carbon monoxide decreases the ability of the blood to carry oxygen to body tissues. 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 to the body can begin very quickly from large amounts of carbon monoxide. How
quickly this happens depends on the length of time a person is breathing the gas and the amount of
the gas he or she breathes in.
     Carbon monoxide poisoning has warning signs. But people have to be awake to recognize them.
Small amounts of the gas will cause a person's head to hurt. He or she may begin to feel tired. The
person may feel sick. The room may appear to be turning around. The person may have trouble
thinking clearly. People develop severe head pain as the amount of gas continues to enter their blood.
They will begin to feel very tired and sleepy. They may have terrible stomach pains.
     Medical experts say carbon monoxide affects people differently. For example, a small child will
experience health problems or die much quicker than an adult will. The general health of the person
or his or her age can also be important. An older adult with health problems may suffer the effects of
carbon monoxide more quickly than a younger person with no health problems. People with heart
disease may suffer chest pains. They may begin to have trouble breathing.