單項選擇題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


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1.單項選擇題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

2.單項選擇題How should you signal the crane operator to move slowly（）.

A.Use one hand to give any motion signal，and place the other hand motionless in front of the hand giving the motion signa
B.Extend arm with the thumb pointing up，and flex the fingers in and out for as long as the load movement is desired
C.First tap your elbow with one hand and then proceed to use regular signals
D.First tap the top of your head with your fist and then proceed to use regular signals

3.單項選擇題How should you signal the crane operator to lower the boom and raise the load（）.

A.Extend arm and point finger in the direction to move the boom
B.Extend arm with thumb pointing downward and flex fingers in and out
C.With forearm vertical and forefinger pointing up，move hand in small horizontal circles
D.With arm extended downwards and forefinger pointing down，move hand in small horizontal circles

4.單項選擇題How should you signal the crane operator to hoist（）.

A.With forearm vertical and forefinger pointing up，move hand in small horizontal circles
B.With arm extended downwards and forefinger pointing down，move hand in small horizontal circles
C.Extend arm with fingers closed and thumb pointing upward
D.Place both fists in front of body with the thumbs pointing upward

5.單項選擇題Damage by（）shall not be considered as handling damage.

A.exposure to inclement weather conditions
B.carelessness
C.the use of improper gear
D.moisture caused by condensation