smile and cry

in the world, human are very funny. we have many kind of emotion. such as: happy, sad... .when we feel happy, we smile. when we feel sad, we cry. but sometimes we are difference. we feel happy or sad, we also cry. not only sad or happy make we cry or smile, exciting also make we hace the same thing. sometimes we do something exciting, after that we laugh. but somebody will cry. sometimes we smile or cry that is not for our selves. we smile for the person who has done well or we smile the person who has done the wrong thing. similarly, cry also has the same situation. sometimes we cry for the people who is very poor or who is very sad. for example: some body lose their children in the war. so human's emotion is diversification.