单项选择题
A.木卡板B.钢筋卡子C.螺栓螺母D.木限位块
A.7%B.15%C.30%D.45%
A.0.001%~0.005%B.0.005%~0.015%C.0.02%~0.03%D.0.05%~0.08%
A.25%NaF+62%NaCl +13%KClB.67%NaF+33%NaClC.60%NaF+25%NaCl +15%Na3AlF6D.40%NaF+45%NaCl +15%Na3AlF6
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