guard pennant

例句：

1. 1. Thewatchman's pennant flewhigh above the castle walls.
   守夜人的旗帜在城堡的城墙上空高高飘扬。
2. 2. The lookout flag was raised towarn of approaching danger.
   瞭望旗被升起，警告即将到来的危险。
3. 3. Thesoldiers stood at attention as the watchman's pennant was lowered.
   当守卫旗降下时，士兵们站得笔直。