[单项选择]

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 40 percent of cancer is related to the diet as well, especially cancer of the colon (结肠). 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 (硝酸) and nitrites (亚硝酸盐), commonly used to preserve color in meats, and other food additives (添加剂), caused cancer. Yet these carcinogenic additives remain in our food, and it becomes more difficult all the time to know which things 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(盘尼西林) to beef and poultry(家禽), and because of this, penicillin has been fou
A. Because of science, most of the foods we eat today are contaminated.
B. It has caused a lack of information concerning the value of food.
C. As a result of scientific intervention, some potentially harmful substances have been added to our food.
D. The scientists have preserved the color of meats, but not of vegetables.