阅读下面短文，在空白处填入一个适当的词，或填入括号中所给单词的正确形式。

    Do you feel ____ difficult to be happy all the time? Now I'll give you some Tips ____ how to make yourself happy. One way is being ____ (self) because unselfishness is the key factor ____ (require) if you want to get along well with others. By ____ (say) being unselfish we mean we ____ not want everything our own way or demand the best share of everything. Another way is to look for good points in ____ people. You will find most people pleasant to go with and it will surely make you happy. Third, you can't expect to be too perfect, ____  don't be too unhappy when you make mistake. Everything will be Ok if you  try to make things right. Finally, it is important to remember that while you  are no ____ (bad) than others, chances you have may not be much better in this case, ____  best way to be happy is to think yourself above other people.