A.50mm B.70mm C.100mm D.150mm
A.燃?xì)夤艿拦鼙诤穸?br /> B.絕緣防腐等級(jí) C.管道焊接質(zhì)量 D.管材強(qiáng)度
A.0.3m B.0.6m C.0.9m D.1.2m