医生检查后宣布了他的体能不合格，无法参加马拉松比赛。

After the medical examination, the doctor declared his ___unfitness to participate in the marathon.

他缺乏经验的情况使他不适合这个管理职位。

His lack of experience shows ___unfitness for this managerial position.

他的工作表现证明了他在这个职位上的不胜任。

His poor performance demonstrated his ___unfitness for the position.