Suppose that 54.3 percent of your country’s population had cancer. That figure might set off a nationwide _______—a search for something wrong with people’s diet, the environment, acidity levels. In fact, that’s the percentage of Americans who show a positive skin response to one or more allergens.
The ______ of allergy—sneezing, itching, rashes—are signs of an immune system running amok, attacking foreign invaders—allergens—that mean no harm. Allergies _______ kill. They just make the sufferer miserable—sometimes for brief periods, and sometimes for life.
Allergies are essentially an epidemic of modernity. As countries become more industrialized, the percentage of population affected by them tends to grow higher. There are remote areas of South America or Africa where allergies are virtually _______.
Here’s how an allergy develops: One day, a body is exposed to a protein in something that seems perfectly ________—the wheat flour, say, in a home-baked muffin. But for some unclear reason, the body looks at the protein and sees trouble. There will be no _______ at first, but the body is remembering—and planning.
That first exposure causes the immune system to produce an antibody called IgE (immunoglobulin E). Then IgE antibodies attach to certain cells, called mast cells, in tissue throughout the body. There they stay like _______ soldiers waiting for war. With a second exposure, even months later, some of the allergen binds with the IgE on the mast cell. This time the mast cell releases a flood of _____ chemicals, which cause inflammation and itching.
There is, unquestionably, a _______ component to allergies. A child with one asthmatic parent has a good chance of developing the condition. If both parents have asthma, the chance of occurrence increases.
Still, the rise in allergies is too rapid to be explained ________ by genetics. “The genetic pool can’t change that much in such a short time,” says Donald Leung, director of an allergy-immunology program in the U.S. “There have to be environmental and _______ factors as well.” Dozens of theories have blamed everyone from urban landscapers for _______ male plants (the ones that produce pollen), to women who don’t breastfeed. Breastfeeding, the theory goes, confers greater protection against allergies.
Another probable factor: diet. “Reduced fresh fruit and vegetable intake, more processed food, fewer antioxidants, and low intake of some minerals—these are all shown to be a _______,” says professor of medicine Harold Nelson, considered one of the foremost experts on allergies in the U.S.
Another prime culprit: environmental pollutants. Exactly what pollutants and in what quantities are a _______ of heated debate. One of dozens of examples: Children who are raised near major highways and are exposed to diesel fumes from trucks register a(n) ______ sensitivity to allergens they already react to.
36. A.awareness | B.shame | C.panic | D.campaign |
37. A.causes | B.diagnosis | C.features | D.manifestation |
38. A.absolutely | B.rarely | C.normally | D.randomly |
39. A.prevalent | B.nonexistent | C.available | D.extinct |
40. A.harmless | B.popular | C.nutritious | D.common |
41. A.warns | B.unease | C.symptoms | D.mistakes |
42. A.brave | B.sophisticated | C.wary | D.skillful |
43. A.infectious | B.poisonous | C.annoying | D.irritating |
44. A.relative | B.hereditary | C.occasional | D.natural |
45. A.mainly | B.definitely | C.necessarily | D.solely |
46. A.behavioral | B.human | C.social | D.emotional |
47. A.avoiding | B.promoting | C.planting | D.favoring |
48. A.venture | B.reason | C.risk | D.chance |
49. A.source | B.pool | C.focus | D.topic |
50. A.flexible | B.mild | C.increased | D.threatening |