A.中硬土B.堅(jiān)硬土C.經(jīng)處理的松土D.凍土
A.調(diào)高熱水溫度B.裝調(diào)壓板C.適當(dāng)加大管徑D.調(diào)大閥門(mén)開(kāi)度
A.回水溫度過(guò)低故障B.回水溫度過(guò)高故障C.氣阻塞故障D.雜物阻塞故障