Smile is a good way to communicate with people that maybe we don't realize.and It can make your life more beautiful.
Smile is a kind of skill that everyone should learn,for example,when you work out a difficult math issue,wear a smile on your face,then you won't feel much too bad;when you are going to help an old man to cross the road that ahead of your house,you smile at her/him,he/she will feel warm and will have a nice mood.
when we get something in trouble ,we also should smile ,smile like a warm water warm our face to face 's distance ,and make our more friendly!