on service的用法和樣例：
例句
- McCain says the benefit will encourage people to leave the service after one enlistment.
邁凱恩說利益會鼓勵人們在服役期間離開軍隊。 - He saw little action in the service and was told the only chance he would have to fly would be as a rear gunner.
在服役期間，肖很少目睹部隊的戰事，他被告知唯一能上天的途徑是作一名飛機上的尾炮手。
辭彙搭配
- on active service 在職(在役
