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單項選擇題

pN電極受到污染后,先用()鹽酸浸泡15~20min,然后用水沖洗干凈,再浸泡在C.氯化鈉溶液中活化。

A.5%,0.1mol/L;
B.10%,0.1mol/L;
C.5%,0.01mol/L;
D.10%,0.01mol/L。

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