Section A Directions: In this section, there is a short passage with 5 questions or incomplete statements. Read the passage carefully. Then answer the questions or complete the statements in the fewest possible words. Please write your answers on Answer Sheet 2. Questions 47 to 51 are based on the following passage. Everyday each of us can renew our efforts to lead a healthier lifestyle. so that we can remain free from illness and pain. Every health expert will advise that as part of any healthy living plan regular exercise should play an important part. For a large majority of people enrolling at the local gym is the answer which will also produce results. There is one negative point however梪pper back pain. What is the cause of upper back pain? In most instances bad posture is the chief criminal. This is often because we spend long periods of time sitting or standing in the same position; generally this tends to be in our place of work. Sitting at desktop computers is one source of this problem! By maintaining the same position the muscles in the upper back which connect the shoulders and help to keep our back straight become tense, stiff and painful. If you find yourself suffering upper back pain it is highly likely that you have strained a muscle, this condition can be extremely painful but are easily treated by your doctor following an accurate diagnosis using X-rays. Keeping fit through physical exercise should not be stopped because of upper back pain, indeed it is an excellent method to prevent this painful problem and can help in relieving symptoms. The use of weights as part of a gym workout may not be advisable, however if under close supervision of a trained professional it is still possible. There are numerous other types of exercise which can be continued whilst suffering upper back pain such as jogging or walking either using a treadmill（塌车) at home or out on the streets. The whole aim is to prevent stiffening of the muscles. The best way to avoid upper back pain is to try to avoid sitting or standing in the same position for extended periods, if it is possible try to have a stretch break every hour or so. This may not be possible therefore, you should try to find ways of jogging your memory throughout the day to keep your posture correct梡ut little notes round your computer screen! It will eventually come naturally and hopefully the problem will disappear. According to health experts, what plays an important role in keeping a healthy lifestyle? Generally,__________is the main cause of upper back pain. If you are suffering upper back pain, most probably, you have___________in the upper back. People suffering upper back pain are advised not to do any weight training exercise in gym unless they are__________ If it is impossible for you to have a stretch break every hour, you&39;d better remember to___________all the time to avoid upper back pain.