题目内容：

根据短文内容及首字母提示完成所缺的单词

  Adults smile less than children do in a day．386 times less，in fact．As a result，we are becoming more and more unhappy and u________．

  All human beings are b________to know how to smile．Children are s________to smile up to 400 times a day．For them，a smile comes from their h_______and pleasure．Unluckily，as we grow o________，we smile less and less．

  “Adults only smile 14 times a day，”says Jamb，a researcher．That means we only smile e________two hours．

  “Life has so many problems that we have forgotten all the r________to smile，”she says．

  We just need to look for things that m________us smile．“Why are you afraid of a smile？”Jamb asks．Trying best to smile is the s______of your happy journey！And anyway，s________is a nice thing to do．

1．________ 2．________ 3．________ 4．________ 5．________

6．________ 7．________ 8．________ 9．________ 10．________