The food we eat seems to have great effects on our health. Although science has made great 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 perhaps eighty percent of all human illnesses are related to diet and forty percent of cancer is related to diet as well. Different cultures are subject to 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(硝酸盐) and nitrites(亚硝酸盐), commonly used to keep color in meats, and other food additives, caused cancer. Yet, these additives remain in our food, and it becomes more difficult all the time to know which things on the packaging labels(标签) of processed food are helpful or harmful. The additives which we eat are not all so direct. Farmers often give penicillin to cows and chick and because of this, penicillin has been found in the milk of treated cows.
Sometimes similar drugs are given to animals not for medicinal purposes, but for financial reasons. The farmers are simply trying to fatten the animals in order to get a higher price on the market. Although the FDA has tried repeatedly to control these, the practices continue.
How has science done a bad service to mankind?

A．Diseases caused by food have been done away with.

B．It has caused a lack of information about the value of food.

C．Some harmful materials have been added to our food.

D．Scientists have made food more expensive to eat.

What are nitrates used for?

A．They help process packaged food.

B．They keep the color in meats.

C．They cure diseases of cows and chickens.

D．They cause the animals to become fatter.

Which of the following statements is NOT true?

A．You can find out harmful additives on the packaging labels of food.

B．Drugs given to animals are not all for medical reasons.

C．Researchers knew about the harm of food additives about 60 years ago.

D．Food may cause forty percent of cancer in the world.

According to the passage, the FDA might be _________.

A．an organization which controls the safety of food

B．a producer which makes additives

C．a factory which processes food

D．a hospital which cures cancer