单项选择题
A.is the SWL of the crane B.are the SWL of the crane C.the SWL of the crane is D.the SWL of the crane are
Official draft measurements should be（）by authorized pe...
单项选择题Official draft measurements should be（）by authorized persons，agreed by both parties involved.
A.executed B.located C.fixed D.measured
Most pedestal crane power is provided by（）.A.Electro-hy...
单项选择题Most pedestal crane power is provided by（）.
A.Electro-hydraulic units B.Steam units C.Independent internal combustion power units D.All of the above
If an attempt is made to hoist a load that exceeds the ...
单项选择题If an attempt is made to hoist a load that exceeds the capacity of an electric winch，an overload safety device causes a circuit breaker to cut off the current to the winch motor（）.
A.when the line pull reaches the rated winch capacity B.after the line pull exceeds the rated winch capacity C.after a short build-up of torque D.immediately
