sentinel [ˈsɛntənəl]

例句:

• Organizers said the Satellite Sentinel Project will be available online Wednesday at www.satsentinel.org.
  来自MSN
• a tall round tower standing sentinel over the river
  镇守在河边的一座高高的圆塔
  
• 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.
  
• The lone sentinel walked toward his post.
  忧愁的哨兵走向岗哨.
  
• The Orlando Sentinel ran a three-paragraph story.
  来自NEWYORKER
• The grim cliff on which the castle stands sentinel over the North Sea.
  来自transf.