1.潜水艇,潜艇
1.海里的,水下的,海底的
1.用潜艇攻击
1.This difficulty has been solved by shuttle-submarined, which will always be ready to take people to the surface.
这一困难由于往返舰艇的出现而得到解决。该舰艇可以在任何时候将人们带到地面。