通过控制导航条的状态来跟踪和展示用户当前位置很困难，成本很大时，用它来替代标签。

Use instead of tabs when it would be prohibitively expensive to track and display the current location of the user as a state in the navigation control.

youdao

低空导航与夜视寻的红外吊舱，尽管它是设计用来精确投掷激光制导炸弹的，但它还能够用来帮助我们确认被救援者的位置并且连续跟踪地面与空中的目标。

The LANTIRN pod, though it's designed to deliver laser-guided bombs precisely to a target, allows us to locate the survivor and keep track of things on the ground and in the air.

youdao