in action

US /ɪn ˈækʃən/
UK /ɪn ˈækʃən/
"in action" picture
1.

投入使用, 在行动中

doing something or operating, rather than being still or inactive

:
It's great to see the new machine in action.
很高兴看到新机器投入使用
The coach likes to see his players in action during practice.
教练喜欢在训练中看到他的球员表现出色