in high keep

例句：

1. 1. The soldiers in high keep were vigilant at the border.
   边防的士兵保持高度警惕。
2. 2. The police are in high keep, watching for any suspicious activity.
   警方高度戒备，监视任何可疑活动。
3. 3. The athletes are in high keep, preparing for the upcoming competition.
   运动员们高度戒备，为即将到来的比赛做准备。