阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填人一个适当的词或使用括号中词语的正确形式填空。
Do you feel   1  difficult to be happy all the time? Now I’ll give you some tips   2  how to make yourself happy. One way is being unselfish because __3__ (self) is the key factor  4  (require) if you want to get along well with others. By   5  (say) being unselfish we mean we should not want everything our own way or demand the best share of everything.   6 way is to look for good points in other people. You’ll find most people pleasant to go with and it will surely make you happy. Third, you can not expect to be too perfect,  7 don’t be too unhappy when you make a mistake.  Everything will be OK if you try to make things right. Finally, it is important to remember while you are no  8_  (bad) than others, chances 9  you have may not be much better. In this case,  10_ surest way to be happy is to think yourself above other people.