Europe's merchant ships spew out around a third more carbon than aircraft do, and nobody is going after them.

欧洲商船排放的碳比飞机多三分之一左右，但没有人去追究它们。

youdao

Merchant ships salute each other by dipping the flag.

商船互相点旗致敬。

《新英汉大辞典》

Were men for the Navy recruited from men on merchant ships?

海军的人员是从商船的人员中征募的吗？

《新英汉大辞典》

About twenty countries have sent warships to the area to protect merchant ships.

VOA: special.2009.05.27

Already, the line between peaceful merchant ships and naval ones is blurring a little.

ECONOMIST: Piracy and private enterprise

Navies are also starting to deploy seamen on merchant ships, something hitherto rare unless the cargo was military.

ECONOMIST: Piracy and private enterprise

This was a three-way contest between merchant ships, German submarines and Allied destroyers.

FORBES: Booked: World War II's Battle of the Atlantic in "A Measureless Peril"