题目内容：

Stores, farmer markets, gas stations and restaurants have been interested in the organic(有机的) food. However, it can be difficult to tell natural foods from organic foods. Most people don’t know that there is a major difference between the two foods. No one seems to be able to determine which is which, creating a lot of confusion for people who are truly concerned with buying the best and healthiest products.

In 2000, the United States Department of Agriculture (USDA) published its official position on organic foods and made its production controlled by a strict law. While there are several standards for organic foods, foods must be grown without the use of antibiotics(抗生素)，growth hormones(激素)，chemical things and so on. The leaves of plants are one of the best choices.

On the other hand, natural foods have no legal rules, and are not controlled by any law. The USDA does require that seller should list the parts of natural foods, but there are no official rules for the amount of natural parts a food must contain. A natural food is usually considered to contain less chemical things, though there is no way to keep an eye on the product.

The USDA has guidelines for organic production. When considering buying organic foods, you must take into consideration that the organic meat, eggs and milk products must come from animals that are given no antibiotics or growth hormones.

Due to higher labor costs, organic products cost 40% to 120% more compared with their natural foods. The most important thing to remember is to eat a variety of healthy foods, organic or natural foods. Eating more fruits, vegetables, low-fat and whole grains will be good for our health.

1.What can be used in growing organic foods?

A. Chemical things.     B. Antibiotics.

C. The leaves of trees.  D. Growth hormones.

2.What is the attitude of the author towards the quality of natural foods?

A. Worried.         B. Interested.

C. Unconcerned.     D. positive.

3.The passage is developed ______.

A. by space         B. by comparison

C. by process       D. by time

4.What may be the main idea of the text?

A. The advantages of organic foods.

B. The function of organic foods.

C. The differences between natural foods and organic foods.

D. The importance of organic foods and natural foods.