sentinel

释义

n. 哨兵, 标记\nvt. 警戒, 守卫\n[计] 标记 stand sentinel 站岗，放哨，守卫

例句

She said it is important to remember that in villages, there will always be an increasing number of sentinel birds between vaccination campaigns as chicks are constantly hatching.

她说，在农村，在接种疫苗的战役之间总是存在数量不断增长的"哨兵"禽类，因为小鸡会不断地孵化出来。 意识到这一点是很重要的。

Moreover, at the gateway of every reading lesson stood sentinel an array of words, with separated syllables, and forbidding accent marks like fixed bayonets, barring the way to the infant mind.

在每一课文的入口，都排列着一队音节分开的生字的哨兵，禁止通行的重音符号就像一把把瞄准的刺刀，阻挡了小孩的心的进入通道。