BRB
abbreviation/ˌbiː ɑː ˈbiː/
/ˌbiː ɑːr ˈbiː/
(informal)- (especially in emails, messages sent using an instant messaging service, etc.) be right back(when you have to leave your computer, etc. for a short time)
马上回来（全写为 be right back，尤用于电邮、即时消息等）