单项选择题
A.yaw joint B.sway joint C.slip joint D.flex or ball joint
The depth over a shallow patch，（）about 1．5 miles southe...
单项选择题The depth over a shallow patch，（）about 1．5 miles southeastward of Nanshan Tou lighthouse，reduces to 8 meters.
A.lay B.lies C.being lain D.lying
The danger associated with using carbon dioxide in an e...
单项选择题The danger associated with using carbon dioxide in an enclosed space is（）.
A.frostbite B.skin burns C.asphyxiation D.an explosive reaction
The bottom row of plating next to the keel of a lifeboa...
单项选择题The bottom row of plating next to the keel of a lifeboat is known as the（）.
A.sheer strake B.bilge strake C.garboard strake D.keel rib
