We don’t think the experiment is ______ failure. At least we have gained ______ experience for future success.

A．the; a

B．a; /

C．a; an

D．the; the

不属于全面腐蚀失效的是（）

A、露天仓库钢筋锈蚀失效

B、异种金属连接处的锈蚀失效

C、管子法兰（凸缘）接头垫圈缝隙内的腐蚀失效

D、冷凝管向上面内管壁的腐蚀穿孔失效