单项选择题
A.maximum counter weight required B.minimum horsepower required C.hoist rope strength D.allowable load
The boom indicator tells the operator at what angle the...
单项选择题The boom indicator tells the operator at what angle the boom is compared to the（）.
A.horizontal position of the boom B.vertical position of the boom C.horizontal position of the load being lifted D.vertical position of the load being lifted
The boom indicator on a crane will indicate the（）.A.len...
单项选择题The boom indicator on a crane will indicate the（）.
A.length of the boom B.angle of the boom C.lifting capacity of the boom D.direction of the boom
Stop（）the derrick at once，the gooseneck is bent.A.to us...
单项选择题Stop（）the derrick at once，the gooseneck is bent.
A.to use B.to operate C.maneuvering D.using
