材料能够不发生过量弹性变形的能力是指( )。
A．刚度
B．塑性
C．韧性
D．疲劳性
参考答案：A
A．闭合s1和s2，断开s3
B．闭合s1和s3，断开s2
C．闭合s2和s3，断开s1
D．闭合s1、s2和s3
During which condition should the operator of a pedestal crane shutdown operations?（）
A.Bunkering barge alongside
B.Potable water spill on deck
C.Crane hydraulic hose bursts
D.Trim greater than 4 feet
