根据句意，用括号内所给单词的适当形式填空。

1. The little boy is too young to get _______ (dress).

2. The soldiers were _______ (exhaust) after a month's fight.

3. Their ideas all sound so _______ (convince).

4. Girls like reading stories with happy _______ (end).

5. I have heard that one bear _______ (flee) from the zoo last night.