A.停爐 B.關(guān)小閥門(mén)開(kāi)度保壓 C.切段總管閥門(mén)
A.工具鋼 B.普碳鋼 C.不銹鋼 D.橋梁用鋼
A.0.211% B.2.11% C.21.1% D.0.0218%