阅读理解。 Feel tired lately? Has the doctor said he can't find, even with the most advanced equipment, anything wrong with you? Then consider this, you might be in a state of sub-health. Sub-health, also called the third state, is explained as a borderline state between health and disease. This is believed to be caused by the stress people have in their everyday lives. According to a survey by the World Health Organization, over 45 percent of sub-healthy people are middle-aged or elderly. The percentage is even higher among people who work in management positions as well as students at exam-time. Symptoms (症状) include a lack of energy, depression, slow reaction, insomnia (失眠),nervous, poor memory, or sometimes shortness of breath, sweating and aching in the waist and legs. Medical experts are offering some advice to reduce pains. They consider the key to preventing and recovering from sub-health is to form good living habits, exercise regularly, and take part in open air activities. As for meals, people are advised to eat less salt and sugar. They should also eat more fresh vegetables, fruits, and fish, as they are rich in vitamins and are important to the body. They also say that a balanced diet is very helpful in avoiding sub-health. Anyhow, work is not all of the life. Your life and work are an entire whole. Satisfy your needs, create calmness in your day and renew your spirit. You will find that focusing on forming more balance in your life can help your work improve, You will be more relaxed, better able to focus and better able to produce high quality work. 1. What is the meaning of the 'sub-'in the word 'sub-health'? A. Of poor quality. B. Special. C. Sick.. D. Not quite. 2. From the passage, _____ may cause the state of sub-health. A. injury B. sickness C. life stress D. incident 3. _____may not be one of the symptoms of sub-health. A. Eating too much B. Feeling tired often C. Slow reaction D. Shortness of breath 4. The main idea of the 5th paragraph is ______. A. that medical experts are offering some advice to reduce pains B. what we should do to prevent and recover from sub-health C. to form good living habits and exercise regularly D. that we should go to take part in open air activities