One possible answer to Warm-up: In my opinion, the following are the major factors affecting our health. Firstly, the diet is the key factor affecting our health. We had better take in a variety of enough nutrition including protein, carbohydrates, vitamins and so on so as to keep us healthy. Secondly, proper exercises are also vital to our health. Exercises can keep us energetic, fit and healthy. Countless studies have shown that those who do exercises regularly have a much lower risk of heart disease and certain cancers. Moreover, exercises can keep us from getting too fat. Obesity is now called the new threat to human being's life besides AIDS and cancers. Thirdly, a good attitude towards life also contributes a lot to health. If we want to be healthy, we should always keep optimistic. An optimistic attitude can relieve us of tension and stress. Finally, a regular life is inseparable from a good health. A regular life can help keep a balance in our body. On the contrary, if we live irregularly, our biological clock will be disturbed. Thus our health will be adversely affected.

Possible Answers to the Questions for Text Comprehension

1. One aspect is how we eat; another aspect is exercise; the final aspect is our mental attitude about life.
   
2. Because they eat much more fruit, vegetables, and grains. They also consume much more fiber. These people eat less meat, so they get fewer calories from fat.
   
3. Because they do more physical work, and since most of them do not have cars, they walk or ride bicycles.

Key to the Exercises about the Text

I. Vocabulary:

II. Structure:

1. 1) stop to buy some vegetables and fruits
   2) stop writing on your paper immediately
   3) stop working
   4) stops to consult a dictionary for new words
   
   
2. 1) 似乎，后面跟 "that" 从句
   2) 好像，后面跟形容词表语
   3) 好像，后面跟不定式表语
   4) 好像，后面跟名词表语
   5) 好像，后面跟不定式表语
   6) 好像，后面跟不定式表语
   
   
3. 1) since we departed at the railway station last year
   2) Since it is late
   3) many years since
   

III. Translation

1. The prices of agricultural products directly affect farmers' income.
   
2. His response showed his view on students' cheating on exams.
   
3. As people's life improves, they consume an increasing quantity of such nutritious foods as meat, poultry, eggs and so on.
   
4. As a singer, her success has much to do with her talent and family background.
   
5. It seems that only a competition can decide who is the winner.
   
6. I have benefited a lot from his positive advice