A、They refer to transgenic organisms. B、They are harmful to the environment. C、They are grown in green and clean ways. D、They ar

Choosing what to eat is no longer as easy as it once was. Stores offer all kinds of foods and snacks and we have to make many choices. When we choose what to buy and eat, we had better think about if the food will give us the nutrients we need.
    Some nutrients help build our body and make it stronger. [12]Protein, for example, is good for our muscles. Fish, meat and beans contain lots of protein. Calcium, which is found in eggs, milk and other dairy products, is good for our bones and teeth. We should also eat carbohydrates, the main fuel for our body, which we can get from bread, rice and noodles. [13]Other nutrients help keep our body functioning well. Vitamins, fibre and minerals, which we can get from eating vegetables and fruits, help our body fight disease and give us energy.
    But the choices we make are not just about nutrition. Many people today make choices about their eating habits based on what they believe. Eating habits become part of who we are: people become vegetarians either because they believe it is healthier not to eat meat or [14]because they do not think we should kill animals for food. We also make choices based on how the products are grown or made: [15]environmentally friendly foods, or "eco-foods", are made by companies who have tried to use green and clean ways to make the foods. Organic vegetables are vegetables that are grown without chemicals which can be harmful to human beings and the environment.
12. What does the speaker say about protein?
13. What should we eat in order to keep our body functioning well?
14. What do we learn about the vegetarians?
15. What is said about the "eco-foods"?