根据短文内容，从下框的A一F选项中选出能概括每一段的主题的最佳选项。并将答案涂在答题纸上相应位置。选项中有一项为多余选项。
A. Be optimistic
B. Stay close to friends
C. Act as if you are happy
D. Make somebody happy
E. Exercise regularly
F. Be grateful
Happiness is a choice. To be happy at all times, you need to make happiness a habit and not just an act. I believe that the following points will show you how to stay happy no matter what happens.
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Gratitude is a sign of appreciation and you ought to show appreciation for life. Always wake up every morning in acknowledgement that you have a list of things you should be thankful for, for example, I woke up this morning, I have food on my table, I have clothes to wear, I have a good paying job, the skies are beautiful and the atmosphere is great. By the time, I am sure that you will feel better already.
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Unhappiness can result from stressing our bodies and minds. Scientists believe that 20 minutes of exercise can make you happy regardless of how sad you may be. Exercise raises your heart rate. As your heart begins to pound, certain hormones（荷尔蒙）are released which create a sense of total well being and you begin to feel well again, the mind stress is gone and everything is under control. Another thing you can do is to take a walk; this works for me all the time. When you take a walk, you are able to think over matters that are bothering you and come up with solutions to them.
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“The best way to cheer yourself is to try to cheer somebody else up.” Said Mark Twain. When you sow happiness, you gain happiness. Mother Teresa knew this secret so well; she devoted her life to helping others even if it simply meant putting a smile on someone’s face. Here are two of her famous quotes: “A life not lived for others is not a life; let no one ever come to you without leaving better and happier.”
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Change is inevitable（不可避免的）and no situation is permanent. Whenever you are feeling sad or depressed, always remember that it’s temporary and that tomorrow will be better, tough times don’t last but tough people do. Develop a positive attitude, and you will stay happy.
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Smile always, even when you are feeling blue. When the body acts, emotions follow. A smile costs nothing but it creates much, it enriches those who receive it without making those who give poor. Learn to smile and act at all times, it won’t only make you happy, it will also win you happy friends.