TEXT E

　　First read the question.
　　51. The main purpose of the passage is to ____.
　　A. illustrate the features of willpower.
　　B. introduce ways to build up willpower.
　　C. explain the advantages of willpower.
　　D. define the essence of willpower.

　　Read the text quickly and then answer the question.
　　Willpower isn't some immutable trait we're either born with or not. It is a skill that can be developed, strengthened and targeted to help us achieve our goals. 　
　　"Fundamental among man's inner powers is the tremendous unrealized potency of man's own will," wrote Italian psychologist Roberto Assagioli 25 years ago. "The trained will is a masterful weapon," added Alan Marlatt of the University of Washington, a psychologist who is studying how willpower helps people break habits and change their lives. "The dictionary defines willpower as control of one's impulses and actions. The key words are power and control. The power is there, but you have to control it." Here, from Marlatt and other experts, is how to do that: 　
　　Be positive. Don't confuse willpower with self-denial. Willpower is most dynamic when applied to positive, uplifting purposes. 　
　　Positive willpower helps us overcome inertia and focus on the future. When the going gets tough, visualize yourself happily and busily engaged in your goal, and you'll keep working toward it. 　
　　Make up your mind. James Prochaska, professor of psychology at the University of Rhode Island, has identified four stages in making a change. He calls them precontemplation (resisting the change), contemplation (weighing the pros and cons of the change), action (exercising willpower to make the change), and maintenance (using willpower to sustain the change).
　　Some people are "chronic contemplators," Prochaska says. They know they should reduce their drinking but will have one more cocktail while they consider the matter. They may never put contemplation into action. 　
　　To focus and mobilize your efforts, set a deadline.
　　Sharpen your will. In 1915, psychologist Boyd Barrett suggested a list of repetitive will-training activities -- stepping up and down from a chair 30 times, spilling a box of matches and carefully replacing them one by one. These exercises, he maintained, strengthen the will so it can confront more consequential and difficult challenges. 　
　　New Jersey Sen. Bill Bradley was a basketball star with the champion New York Knicks. On top of regular practice, he always went to the gym early and practised foul shots alone. He was determined to be among the best form of the foul line. True to his goal, he developed the highest percentage of successful free throws on his team.
　　Expect trouble. The saying "Where there's a will, there's a way" is not the whole truth. Given the will, you still have to anticipate obstacles and plan how to deal with them.
　　When professor of psychology Saul Shiffman of the University of Pittsburgh worked with reformed smokers who's gone back to cigarettes, he found that many of them hadn't considered how they'd cope with the urge to smoke. They had summoned the strength to quit, but couldn't remain disciplined. The first time they were offered a cigarette, they went back to smoking.
　　If you've given up alcohol, rehearse your answer for when you're offered a drink. If you're expecting to jog but wake up to a storm, have an indoor workout program ready. 　
　　Be realistic. The strongest will may falter when the goal is to lose 50 pounds in three months or to exercise three hours a day. Add failure undercuts your desire to try again. 　
　　Sometimes it's best to set a series of small goals instead of a single big one. As in the Alcoholics Anonymous slogan "One day at a time," divide your objective into one-day segments, then renew your resolve the next day. At the end of a week, you'll have a series of triumphs to look back on. 　
　　Be patient. A strong will doesn't develop overnight. It takes shape in increments, and there can be setbacks. Figure out what caused you to backslide, and redouble your efforts. 　
　　When a friend of ours tried to give up cigarettes the first time, she failed. Analyzing her relapse, she realized she needed to do something with her hands. On her second try, she took up knitting and brought out needles and yarn every time she was tempted to light up. Within months she had knitted a sweater for her husband -- and seemed to be off cigarettes for good. 　
　　Keep it up. A strong will becomes stronger each time it succeeds. If you've successfully mustered the willpower to kick a bad habit or leave a dead-end job, you gain confidence to confront other challenges. 　
　　A record of success fosters an inner voice of confidence that, in the words of Assagioli, gives you "a firm foot on the edge of the precipice." You may face more difficult tasks, but you've conquered before, and you can conquer again.