A smile shows that a person is happy. For example, a person may smile when he or she is pleased with a grade on a test. Or a person might smile if a friend told a funny joke. People smile for many different reasons. But smiles are more than just a way for people to show that they are happy.There are other good reasons to smile often.
First, it is easier to smile than to show unhappiness. In fact, it only takes 17 muscles(肉) to smile. On the other hand, it takes 43 muscles to show unhappiness. So give the muscles in your face a rest and smile!
Second, smiles are nice. People may try to look nice on the outside by exercising or wearing nice clothes. However, there is a famous saying: a smile is the best thing a person can wear. That is because it is easy to be around someone who is smiling and happy. Almost no one wants to be around someone who is unhappy all the time.
Third, smiles are helpful. Both smiling and laughing can quickly spread from one person to another. If one person smiles, people around him or her want to smile, too. Similarly, when a person laughs, people tend to(倾向于) laugh with them. If a person is sad, the best thing to do is to share a smile or laugh. It is the easiest and cheapest way to cheer someone up.
Finally, smiling and laughing are very good for the body. Even if you are mad or sad, try smiling.You'll find that it will be hard to stay mad or sad for very long.