单选题 The food we eat seems to have profound effects on our health. Although science has made enormous steps in making food more fit to eat, it has, at the same time, made many foods unfit to eat. Some research has shown that forty percent of cancer is related to the diet as well, especially cancer of the colon. People of different cultures are more prone to get certain illnesses because of the food that is characteristic in these cultures. That food is related to illness is not a new discovery. In 1945, government researchers realized that nitrates and nitrites (commonly used to preserve color in meats) as well as other food additives caused cancer. Yet, these carcinogenic additives remain in our food, and it becomes more difficult all the time to know which ingredients on the packaging labels of processed food are helpful or harmful. The additives that we eat are not all so direct. Farmers often give penicillin to cattle and poultry, and because of this, penicillin has been found in the milk of treated cows. Sometimes similar drugs are administered to animals not for medicinal purposes, but for financial reasons. The farmers are simply trying to fatten the animals in order to obtain a higher price on the market. Although the Food and Drug Administration (FDA) has tried repeatedly to control these procedures, the practices continue.
单选题 How has science done a disservice to people?
【正确答案】 C
【答案解析】[解析] 本题提出“科学对人类如何造成了伤害?”从整个文章来看，A项过于笼统；而B、D两项内容是错误的，C项“作为科学干涉的结果，一些潜在有害的物质已经添入到了我们的食品中。”最合适。
单选题 What are nitrates used for?
【正确答案】 B
【答案解析】[解析] 根据文章第六行“In 1945, government researchers realized that nitrates and nitrites(commonly used to preserve color in meats)as well as other food additives caused cancer.”句中括弧里的内容是对nitrates and nitrites的解释说明，所以B为正确选项。
单选题 The FDA has tried repeatedly to control ______.
【正确答案】 C
【答案解析】[解析] 根据文中的“Sometimes similar drugs are administered to animals not for medicinal purposes, but for financial reasons. The farmers are simply trying to fatten the animals in order to obtain a higher price on the market. Although the Food and Drug Administration (FDA) has tried repeatedly to control these procedures, the practices continue.”得知“有时给牲畜食用药物并不是为了治病，而是受利益的驱使，虽然FDA再三地试图控制这些行为，但是这种做法仍在继续。”，所以选C。
单选题 The word "carcinogenic" means most nearly the same as ______.
【正确答案】 D
【答案解析】[解析] 本题要求根据上下文猜测单词的词义。上文提到“...nitrates and nitrites...as well as other food additives caused cancer.”紧接着文中提到“Yet, these carcinogenic additives remain in our food...”，所以根据上下文，carcinogenic应该是cancer-causing的意思，表示这些致癌的添加成分存在于我们的食物中。
单选题 Which of the following statements is NOT true?
【正确答案】 A
【答案解析】[解析] A选项与倒数第四行“Sometimes similar drugs are administered to animals not for medicinal purposes, but for financial reasons.”意思相悖。