客运专线后张法预制梁的抽拔橡胶棒或金属螺旋管在任何方向与设计位臵的允许偏差要求是() ["A、距跨中4m范围≤4mm,其余≤6mm","B、距跨中5m范围≤5mm,其余≤10mm","C、距跨中4m范围≤10mm,其余≤20mm"]
下列不属于静电特性的是()。 ["A、电压高","B、电量低","C、电流小","D、静电泄漏快"]
以下有关RMI指示的角度哪个是错误的:(). ["飞机的真航向","飞机的磁航向","电台磁方位","飞机磁方位"]
当客运专线预制梁的保护层采用细石混凝土垫块时,其()能力和抗压强度应高于构件本体混凝土,且水胶比不大于() ["A、抗腐蚀,0.4","B、抗渗,0.4","C、抗腐蚀,0.35"]
下列导航设备中,属于航路导航的是()。 ["航向信标","全向信标","下滑信标","指点信标"]
简述抵押与质押的共同点?