sentinels

例句:

• The sentinels who paced the ramparts announced that the...army was in sight.
  来自Ld Macaulay
• Sentinels were placed at all the approaches to the farm.
  在去农场的所有路上都布置了哨兵.
  
• Sentinels stopped them, enquired, passed them.
  哨卡拦阻他们, 盘问他们, 放他们通行.
  
• Their pink buds , thrust up like arrows , seemed sentinels watching over Baiyangdian Lake.
  粉色荷花箭高高的挺出来, 是监视白洋淀的哨兵吧!
  
• Sentinels paced the rounds day and night.
  来自Ld Macaulay
• Using animals as sentinels for human health is not a new concept.
  来自SA