阅读理解。
An allergy (过敏反应) is a strong reaction to a substance. Many things can cause
allergies. The most common cause is pollen (花粉), which is usually produced by trees in
the spring, grasses in the summer and weeds in the fall, as part of their reproductive
process.
Other causes include organisms, chemicals, plants and dead skin particles (微粒) from
dogs and cats can also cause allergic reactions. So can insect stings and some food.
The most common kind of allergic reactions is itchy (痒的), watery eyes and a blocked
or watery nose. Allergies can also cause red, itchy skin. Some reactions can be life-
threatening, for example, when breathing passages become blocked.
It is not always easy to avoid allergies. Drugs may offer an effective treatment.
Another treatment used in some cases is called immunotherapy (免疫疗法). A patient is
injected with small amounts of the allergy-causing substance. The idea is that larger and
larger amounts are given over time until the patient develops a resistance in his body.
In the United States, experts estimate that up to 8% of young children have food
allergies. Every year these allergies cause about 30,000 cases with severe reactions that
require immediate treatment. It can result in breathing trouble and in some cases death.
It is said that about 100 to 200 people will die. It says most of the reactions are caused
by peanuts and tree nuts like walnuts.
People can also be allergic to medicines. The American Academy of Allergy, Asthma and
Immunology says about 10% of bad reactions to commonly used medicines are allergic. In
other words, a person's immune system overreacts and produces an allergic reaction. The
most common reactions include skin rashes (皮疹), itching, breathing problems and swelling
in areas such as the face.
1. Allergies seldom occur in winter because _____. [ ]
A. plants don't flower in cold weather
B. people usually wear thick clothes
C. pollen is active below freezing point
D. the weather is not too cold for viruses
2. What will happen if one's breathing passages get blocked? [ ]
A. It is nothing serious.
B. One's life is at risk.
C. One has to be sent to hospital.
D. One is sure to breathe easily.
3. According to immunotherapy, the patient is supposed to _____. [ ]
A. take some medicines to produce antibodies
B. have immediate operations
C. be given the allergy-causing substance until he develops a resistance
D. be exposed to enough allergy-causing substances
4. The best title would be "_____". [ ]
A. The ABCs of Allergies
B. The Cause of Allergies
C. The Treatment of Allergies
D. The Prevention of Allergies
