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Medical experts have suspected for many years that there is a strong link between what a person eats and cancer. A team of Chinese and American scientists did the study. About thirty thousand people from
the ages of 40 to 69 took part in the study. They were from the Northern Central Chinese Area of Linxian. Most of them took vitamines and minerals every day for five years.
Linxian was chosen because the people there have an extremely high rate of cancer of stomach and esophagus(食道). Researchers believe that fungus and molds (真菌和霉菌) in local foods nay be partly responsible for the high cancer rate. Researchers divided those into eight groups. Seven of the groups received different mixtures of vitamines and minerals daily. The amounts of the vitamines and minerals were 1 to 2 times than what American health officials say is needed. The eighth group received sugar pills that had no effect. Those who seemed to gain the most received a mixture of a form of vitamine A called β-carotene (β-胡萝卜素), vitamine E and the mineral selenium. The vitamine and mineral are believed to prevent damage to cells (细胞) caused by cancer-causing substances (物质). Researchers reported a 13 percent drop in cancer rates in those who tookβ-carotene, vitamine E and selenium (硒). They also found a 10 percent drop in the number of deaths caused by strokes (中风) from bursting blood vessels(血管).
1.What do you think may cause cancer according to the passage?
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2.Why do the people in Linxian have a high rate of cancer of stomach and esophagus? It is possibly because ________.
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A.they took lots of vitamines and minerals every day
B.they received a mixture of vitamine A and vitamine E
C.they ate a kind of local food which contains fungus and molds
D.the passage doesn't tell us
3.What should the people in Linxian eat if they want to reduce cancer rates?
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A.β-carotene and minerals
B.food with fungus and molds
C.vitamines and sugar pills
D.β-carotene, vitamine E and selenium
4.What is the main idea of the passage?
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A.Why do the people in Linxian have a high rate of cancer of stomach and esophagus?
B.Scientists try to find out ways to prevent cancer.
C.Medical experts have a experiment on cancer patients.
D.Scientists try to find out if there is a link between cancer and food.