单项选择题
A.At a 45° angle
B.At right angles
C.4 feet aft of the heel of the boom
D.Parallel to the boom
单项选择题 When using slings，cargo handlers should take all the following precautions except（）.
单项选择题 When instructing a crew member concerning the right way to lift a weight，you would instruct him to（）.
单项选择题 When discharging oil from an oil tanker the instantaneous rate（）60 liters per nautical mile.