A.10mmB.20mmC.30mmD.40mm
A.自動監(jiān)測B.報警監(jiān)測C.遠程監(jiān)控D.固定監(jiān)測
A.折射率發(fā)生B.應(yīng)力發(fā)生C.反射波發(fā)生D.線路發(fā)生