根据句意和汉语提示，填写单词。

1. His brother is a _____(军人). He joined the army five years ago.

2. We must _____(面对) these problems and find ways to get over them.

3. The old man _____(将……视为) the poor boy as his own son.

4. _____ (除非) we work hard, we will hardly ever learn English well.

5. There is a popular saying in sports meeting, "_____(友谊) first, competition second."