Medical experts have suspected for many years that there is a strong link between what a person eats and cancer. They say a new study provides the first evidence that vitamins could reduce a person"s chance of developing cancer. A team of Chinese and American scientists did the study. They are from American National Cancer Institute and the Cancer Institute of the Chinese Academy of Medical Sciences in Beijing.
The Journal of the National Cancer Institute
published the results of the study. About thirty thousand people between 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 vitamins 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. Researchers believe that fungus and molds in local foods may be partly responsible for the high cancer rate. Researchers divided those into eight groups. Seven of the groups received different mixtures of vitamins and minerals daily. The amounts of the vitamins and minerals were 1 to 2 times greater 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 vitamin A called D-carotene, vitamin E and the mineral selenium. The vitamin and mineral are believed to prevent damage to cells caused by cancer-causing substances. Researchers reported a 13 percent drop in cancer rates in those who took D-carotene, vitamin E and selenium. They also found a 10 percent drop in the number of deaths caused by strokes from bursting blood vessels.
Scientists warn that it is too soon to know if the effect would be the same among people in other countries. They note that the people in Linxian eat foods that lack necessary vitamins and minerals. Chinese officials will continue to record the health records of the people in Linxian for many years. For now officials reportedly are considering using the results of the study. They want to find a way to improve the health of people in Linxian and other small towns in China.
单选题
Among the scientists that did the study, there are more Chinese than Americans.
【正确答案】
C
【答案解析】[解析] 文中只提到“一个由中美科学家组成的小组进行了这项研究”(A team of Chinese and American scientists did the study.)，并没有提及将美国科学家和中国科学家人数进行比较，所以题干的描述是“没提到”，故选C。
单选题
The study lasted for about five years.
【正确答案】
A
【答案解析】[解析] 第一段最后一句提到“Most of them took vitamins and minerals every day for five years. (大部分研究对象每天服用维他命和矿物质，服用了5年)，由此可以推断出这项研究持续了大约5年，所以本题是正确的，故选A。
单选题
The rate of cancer of stomach and esophagus in Linxian is the highest in China.
【正确答案】
C
【答案解析】[解析] 文中第二段首句讲到林县胃癌和食道癌的发生率极高(extremely high rate of cancer of stomach and esophagus)，并没有将胃癌和食道癌的发生率在中国范围内进行比较，所以并不知道是不是最高的，随后一句话讲到当地食物中的菌类和霉菌是造成胃癌和食道癌高发的原因，这是一个新的话题，所以题干的表述“林县胃癌和食道癌的发生率是中国最高的”为“没提到”，故选C。
单选题
Fungus and molds in local foods may be partly responsible for the high cancer rate in Linxian.
【正确答案】
A
【答案解析】[解析] 文中第二段第二句提到“Researchers believe that fungus (菌类) and molds (霉) in local foods may be partly responsible for the high cancer rate.”，该句的说法与题干的说法相同，故选A。
单选题
All those people who took part in the study received vitamins and minerals.
【正确答案】
B
【答案解析】[解析] 文中第二段介绍了如何进行实验，其中提到研究人员将研究对象分为八组，其中七组每天服用维生素和矿物质(Seven of the groups received different mixtures of vitamins and minerals daily.)，而第八组服用的是对健康没有影响的糖片(The eighth group received sugar pills that had no effect.)，由此可知，不是所有参加研究的人都服用维他命和矿物质，所以题干的表述错误，故选B。
单选题
The results of the study are of great significance to people everywhere.
【正确答案】
B
【答案解析】[解析] 根据题干可知，题干的内容涉及该项研究的意义，所以相关内容最有可能在文章的最后部分出现。最后一段首句讲到“科学家提醒目前太早了还不能确定其他国家的人们是否受相同的影响”，而且最后一句中仍然涉及的是林县和中国的其他小城市(Linxian and other small towns in China.)。由此可判断出题干的表述“研究结果对世界各地的人来说意义重大”错误，故选B。