The Union used hot air balloons and submarines.

联邦曾使用热气球和潜艇。

youdao

The principles are similar to sonar used by boats and submarines.

原理类似于船和潜艇的声纳系统。

youdao

The two sides have recently signed procurement deals covering helicopters and submarines.

双方最近双方签署的采购协议包括直升机和潜艇。

youdao

And robotic submarines are being used to try to stop the leak -- a process that could take weeks.

VOA: special.2010.05.01

Thank goodness for Congress and the Admirals that think it's important because women are going to be on submarines."

VOA: special.2010.05.21

Critics of the idea say the living areas in submarines are too small and narrow for men and women to serve together.

VOA: special.2010.05.21

That suggests that the Navy has more frigates and submarines than it really needs.

ECONOMIST: The future of the Royal Navy

The merged company would be the only one that could produce nuclear ships and submarines for the U.S. Navy.

FORBES: Focus On The Forbes 500s

The company provides data storage and image capturing from aircraft, satellites and submarines for intelligence gathering and defense purposes.

FORBES: Gurus Buy Biotech And Software, Sell Health Care