a merchant banker的用法和样例：
- Mr Menzies, who is a former submariner in the Royal Navy and a merchant banker, is an amateur historian and his theory met with little approval from professionals.
- Harry has kicked around all over the world as a merchant seaman.
- A book in which a merchant records credit sales.
- The scout disguised himself as a merchant.
- This is a merchant ship of 5,000 tons.