A.ABCUB.BSCUC.BTMUD.LGCIU
A.备用刹车关断活门(ALTERNATE SHUT-OFF VALVE)B.双往复活门(DUAL SHUTTLE VALVE)C.双活门(DUAL VALVE)D.备用刹车伺服活门(ALTERNATE SERVO VALVE)
A.有防滞的备用刹车B.无防滞的备用刹车C.不能实施备用刹车D.以上均不正确