单项选择题
A.working on the rig floor B.working over water C.working on the pipe racks D.operating line throwing equipment
A latitude line will be obtained by observing a body （）...
单项选择题A latitude line will be obtained by observing a body （）.
A.on the prime vertical B.on the celestial horizon C.at lower transit D.on the Greenwich meridian
A lashing used to secure two barges side by side，lashed...
单项选择题A lashing used to secure two barges side by side，lashed in an "X" fashion，is called a （）.
A.quarter line B.back line C.peg line D.jockey line
A.scissor wire B.towing wire C.breast wire D.cross wire
