n.留神观察,留心守候,监视
Standing in the watchtower, we admired the surrounding scenes.
我们站在碉楼上, 欣赏四周的景色.
If it isn't, why do they renovate the watchtower?
要不然, 为什么他们要修复了望塔?
The watchtower followed the aircraft by radar.
了望塔通过雷达追踪这架飞机的飞行.