海军士兵

例句：

1. 1. The navy has been keeping watch over the harbor for several days now.
   海军已经监视港口几天了。
2. 2. He served in the navy for many years before retiring.
   他在海军服役多年后退休了。
3. 3. The navy is responsible for maintaining order and security in the waters.
   海军负责维护水域的秩序和安全。