单项选择题
A.annular blowout preventer B.annulus C.accumulator D.automatic choke
A large metallic device，mounted directly in the piping ...
单项选择题A large metallic device，mounted directly in the piping (usually located at the dock near the point where the vapor hose is attached)，designed to prevent the passage of a rapidly moving flame through the piping is called a（）.
A.flame arrestor B.flame screen C.detonation arrestor D.detonation blocker
A large basin cut into the shore，closed off by a caisso...
单项选择题A large basin cut into the shore，closed off by a caisson，and used for dry docking of ships is known as a（）.
A.slipway B.graving dock C.ground warp D.caisson dock
A jack-up drilling unit elevated on the Outer Continent...
单项选择题A jack-up drilling unit elevated on the Outer Continental Shelf must have a fog horn that will sound（）.
A.a 2-second blast every 20 seconds B.a 4-second blast every 20 seconds C.an 8-second blast every 30 seconds D.a 10-second blast every 30 seconds
