A.枝狀管網(wǎng)B.復(fù)線枝狀管網(wǎng)C.環(huán)狀管網(wǎng)D.輻射狀管網(wǎng)
A.熱熔連接B.焊接C.絲扣連接D.法蘭連接
A.給水鑄鐵管B.球墨鑄鐵管C.鍍鋅鋼管D.不鍍鋅鋼管