单项选择题
A.increases as the boom's angle to the horizontal increases
B.is at a maximum when the boom is at a 45° angle to the horizontal
C.increases as the boom's angle to the horizontal decreases
D.decreases as the boom's angle to the horizontal decreases
单项选择题 Why is gas-freeing rarely required for LPG cargo tanks? （）
单项选择题 Why are most break bulk vessels built with the transverse framing system rather than the longitudinal system? （）
单项选择题 While your vessel is docked port side to a wharf，a sudden gale force wind causes the vessel’s stern lines to part. The stern begins to fall away from the dock，and no tugs are immediately available. Which measure(s) should you take FIRST?（）