A.先用高檔大致對(duì)正后,再用低檔慢慢地準(zhǔn)確對(duì)正 B.先用低檔大致對(duì)正后,再用高檔快速地準(zhǔn)確對(duì)正 C.先用低檔大致對(duì)正后,再用中檔慢慢地準(zhǔn)確對(duì)正 D.先用中檔大致對(duì)正后,再用高檔快速地準(zhǔn)確對(duì)正
A.閥箱、閥座孔被刺壞 B.閥箱內(nèi)進(jìn)入雜物 C.閥被卡住 D.上水管線不密封
A、吸入不良產(chǎn)生水擊 B、活塞或閥損壞 C、閥箱座孔損壞 D、連接卡箍松動(dòng)