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
单项选择题 Stop（）the derrick at once，the gooseneck is bent.
单项选择题 On no account（）to be exceeded.
单项选择题 On a ship crane，the load chart relates the allowable load to the combination of boom length and（）.
