单项选择题
With a given load on the cargo hook，the thrust on a cargo boom（）.
A.increases as the angle to the horizontal increases
B.increases as the angle to the horizontal decreases
C.is greatest at an angle of 45° and decreases as the boom is raised or lowered
D.is least at an angle of 45° and increases as the boom is raised or lowered
相关考题
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单项选择题
With a given load on the cargo hook，tension in a single span topping lift（）.
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? （）
A.LPG is compatible with all cargos
B.LPG's high oxygen content makes it nonvolatile
C.Cargo tanks are inspected less frequently than on oil tankers
D.The cargo tanks are used for one type of cargo only -
单项选择题
Why are most break bulk vessels built with the transverse framing system rather than the longitudinal system? （）
A.The transverse system is more resistant to hog and sag stresses
B.The numerous longitudinal frames cause excessive broken stowage
C.The transverse system provides better support to the varying cargo densities on a break bulk vessel
D.The deep web frames interfere with the stowage of break bulk cargo
