单项选择题
When discharging oil from an oil tanker the instantaneous rate（）60 liters per nautical mile.
A.Should not exceed B.Must be up to C.Should exceed D.Should be about
单项选择题 When discharging an oil cargo，the first consideration is to（）.
单项选择题 What is/are the advantage（s）of cranes over conventional cargo booms（）.
单项选择题 What is the purpose of the equalizing beam aboard a crane vessel（）.
