restricted sail area mark

例句：

1. 1. The ship's crewmarked the restricted sail area with a redflag.
   船员用红旗标出了限制航行区域。
2. 2. The pilot carefully marked the restrictedsail area on the map.
   飞行员在地图上小心地标出了限制航行区域。
3. 3.The captain instructed the crew to mark therestricted sail area with caution.
   船长指示船员小心地标出限制航行区域。