If you know first aid methods, you can be calmer and more helpful in case of emergency.

VOA: special.2009.08.11

The military aid always has to be within a certant disatance of the president in case of emergency.

军事助理经常需要,待在总统的一定范围内,以防出现紧急情况。

普林斯顿公开课 - 国际座谈会课程节选