英语翻译

问题描述:

英语翻译
整句话是这样的:But when he looked into the matter he discovered that none of the diplomatic passages commonly identified in these terms involved that particular class of vessel known to the Navy as a ‘gun-boat’,and that many were military rather than naval occasions.

根据上下文,vessel这里是指舰船.
particular class of vessel
特殊级别的舰船
gunboat
炮舰