法兰在操作状态下垫片载荷Hp=π(2b)DGPm,其中m只与垫片()有关。
A.厚度
B.有效宽度
C.材质和形状
参考答案:C
Consumption of the total life-cycle effort in software maintenance is( ) that in software development.
A.less than
B.larger than
C.equal or less than
D.equal or larger than
机坪管网应安装(),每两个机位至少设一个按钮。
A.摄像监控装置
B.紧急停泵装置
C.油泵启动装置
D.电位测试装置