Решение:
- sad — unsad
- wrong — inwrong
- you can't do it — impossible
- relaxed and friendly — unrelaxed and friendly
- not follow the usual rules — irregular rules
- criminal — illegal
- strange — unstrange
- you can't see it — invisible
Ответ: unsad; inwrong; impossible; unrelaxed and friendly; irregular rules; illegal; unstrange; invisible.