A.熱水熱網(wǎng) B.一級(jí)管網(wǎng) C.地溝管網(wǎng) D.閉式管網(wǎng)
A.10% B.30% C.50% D.70%
A.補(bǔ)焊或蓋壓補(bǔ)焊 B.補(bǔ)麻、補(bǔ)灰 C.兩合揣袖 D.更換