merchant captain的用法和樣例：
例句
- United States naval forces have freed the captain of an American merchant ship who was abducted by Somalia pirates last week.
美國海軍讓上周被索馬利亞海盜劫持的美國商船船長重獲自由。 - Meanwhile, more American warships are heading toward a lifeboat where an American merchant navy captain is being held hostage.Humphrey Hawksley reports.
同時，更多的美國軍艦正在追擊一艘救生船，船上有一名被劫持的美國商船船長。
