题目

It’s easy to _____ this math problem. A. work out       B. find out        C. look out 答案：A解析:略   Feel tired lately? Has a doctor said he can’t find anything wrong with you? Perhaps he sent you to a hospital, but all the advanced equipment there shows that there is nothing wrong with you.     Then, consider this: you might be in a state of sub-health（亚健康）.     Sub-health, also called the third state or gray state, is explained as a borderline state between health and disease.     According to the investigation(调查) by the National Health Organization, over 45%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 around exam week.     Symptoms(征兆) include a lack of energy, depression, slow reactions, insomnia(失眠), agitation, and poor memory. Other symptoms include shortness of breath, sweating and aching in the waist and legs.     The key to preventing and recovering from sub-health, according to some medical experts, is to form good living habits, alternate work and rest, 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, fish because they are rich in nutritional elements（营养元素）---vitamins and trace elements—that are important to the body. Nutrition experts point out that it is not good to eat too much at one meal because it may cause unhealthy changes in the digestive tract(消化道). They also say that a balanced diet is very helpful in avoiding sub-health. 1.When you are in a stat of sub-health, you should _____________. A．stay home and keep silent B．go to a doctor and buy some medicine C．not consider it very serious D．find out the reasons and relax yourself 2. Middle-aged people may be easy to get sub-healthy because ____________. A．they have used up their energy B．they have lost their living hopes C．they have more pressure in life and work D．they have changed their way of life 3. The key to preventing you from falling into a state of sub-health is to ____________. A．keep on working regularly B．go to sleep a bit earlier C．form good living habits D．take medicine if necessary 4. The underlined word “ alternate” in this passage means _____________. A. arrange by turns       B. cause to take place C. make up for                  D. keep away from