sentinel的例句（sentinel在句子中的用法）

• sentinel duty 哨兵义务
• The lone sentinel walked toward his post. 忧愁的哨兵走向岗哨.
• We gave the watchword, and the sentinel let us pass. 我们说出口令, 哨兵就把我们放过去了.
• a tall round tower standing sentinel over the river 镇守在河边的一座高高的圆塔