A.從熱力站至用戶的供水管網 B.從熱力站至用戶的供回水管網 C.從熱源至熱力站的回水管網 D.從熱源至熱力站的供回水管網
A.50% B.60% C.80% D.100%
A.30m,4m B.25m,3.5m C.20m,3m D.15m,2.5m