这座古老的石桥因其经久耐用而闻名。

The ancient stone bridge is famous for its ___permanence.

他在公司工作了五年后终于获得了正式职位。

After five years at the company, he finally got a ___permanent position.

在频繁搬家的军人家庭中，稳定的朋友关系成为了孩子们生活中的恒常因素。

In military families that move frequently, stable friendships become the ___permanence in children's lives.