Definition: an activity that is planned in order to achieve something Level: C1
地震后，一场大规模的救援行动展开了。
Following the earthquake, a large-scale rescue ___operation was launched.
联合国授权了一项军事行动以运送人道主义援助。
The UN authorized a military ___operation to deliver humanitarian aid.
这次维和行动的成功受到了广泛赞扬。
The success of the peacekeeping ___operation was widely praised.
