其主要职责是管理领导人的文电材料和密码,负责领导人办公处的保密工作,承办领导交办的机密事项,为领导提供必要的帮助和服务,这是( )
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧