sentry

名词 sentry:

1. a person employed to watch for something to happen
   同义词：lookout, lookout man, sentinel, watch, spotter, scout, picket

1. No one was excluded from sentry duty.
   人人都得站岗放哨。
2. The sentry had orders to shoot on sight.
   哨兵奉命一发现有动静就立即开枪。
3. The sentry challenged the stranger at the gates.
   哨兵查问在门口的陌生人。
4. An assigned position or station, as of a guard or sentry.
   哨站，岗位如卫兵或哨兵的指派的站岗位置