用所给词的正确形式填空。
1. Sometimes they have _____ (agree) and decide not to talk to each other.
2. By _____ (regard) problems as challenges, they will become happier.
3. Think of something _____ (bad), you will find your problems are not so terrible.
4. She decided _____ (solve) the problem by _____ (talk) with her mother.
5. It's _____ (fair) for us to lose the chance.
