这块木板比那块更硬，更适合做架子。

This board is ___stiffer than that one, making it better for shelves.

新老板的规章制度比前任更加严格。

The new boss's policies are ___stiffer than the previous one's.

面试时他的举止比平时显得更加拘谨。

His behavior was ___stiffer than usual during the interview.