A.加速度
B.速度
C.位移
D.动能
ACD
What is meant by the term TOPPING THE BOOM?()
A.Lowering the boom
B.Raising the boom
C.Spotting the boom over the deck
D.Swinging the boom athwartships
架空光(电)缆支撑吊线宜用7股镀锌钢绞线。