单项选择题
A.玻璃 B.玛瑙 C.铂金 D.陶瓷 E.不锈钢
A.二价 B.三价 C.四价 D.五价 E.六价
A.白光 B.单色光 C.可见光 D.紫外光 E.特征波长锐线辐射光
A.283.3,357.9,228.8,253.7 B.283.3,253.7,228.8,357.9 C.357.9,253.7,228.8,283.3 D.228.8,283.3,253.7,357.9 E.357.9,253.7,228.8,283.3
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