A.涂防腐絕緣層 B.陰極保護(hù) C.犧牲陽(yáng)極 D.噴緩蝕劑
A.1/4~1/3 B.1/3~2/3 C.1/2~1/3 D.1/2~2/3
A.平行 B.垂直 C.相交 D.成45°交角