spring into action

Từ điển Oxford Advanced Learner 8th

ˌspring into ˈaction | ˌspring into/to ˈlife idiom
(of a person, machine, etc.)to suddenly start working or doing sth
•‘Let's go!’ he said, springing into action.
•The town springs into life (= becomes busy) during the carnival.
Main entry: ↑spring_idiom