An allergy is a strong reaction to a substance. Many things can cause allergies.

An allergy is a strong reaction to a substance. Manythings 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 reproductiveprocess.

Other causes include organisms, chemicals, plants anddead skin particles from dogs and cats can also cause allergic reactions. Socan 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 belife-threatening, for example, when breathing passages become blocked.

It is not always easy to avoid allergies. Drugs mayoffer an effective treatment. Another treatment used in some cases is calledimmunotherapy. A patient is injected with small amounts of the allergy-causingsubstance. The idea is that larger and larger amounts are given over time untilthe patient develops 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 about30,000 cases with severe reactions that require immediate treatment. It canresult in breathing trouble and in some cases death. It is said that about 100to 200 people will die. It is said that most of the reactions are caused bypeanuts and tree nuts like walnuts.

People can also be allergic to medicines. The AmericanAcademy of Allergy, Asthma and Immunology says about 10％ of bad reactions to commonly used medicines areallergic. In other words, a person’s immune system overreacts and produces anallergic reaction. The most common reactions include skin rashes, itching,breathing problems and swelling in areas such as the face.

1.Allergies seldom occur in winter because ________.

A. plants don’t usually flower in cold weather

B. people usually wear thick clothes

C. pollen is active below freezing point

D. the weather is too cold for viruses

2.What will happen if one’s breathing passages getblocked?

A. It is nothingserious.               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 supposedto________.

A. take some medicines to produce antibodies

B. have immediate operations

C. be given the allergy-causing substance until thepatient develops resistance

D. be exposed to enough allergy-causing substances

4.The best title would be _______.

A. The ABCs ofAllergies              B. The Cause of Allergies

C. The Treatment ofAllergies          D. ThePrevention of Allergies

试题答案

【答案】

1.A

2.B

3.C

4.A

【解析】

试题