下列炉渣氧化物按碱性强弱排列的顺序排成是()
A、CaOMnOFeOMgO
B、MgOCaOMnOFeO
C、CaOMgOMnOFeO
参考答案:C
国家现行《职业病名单》中规定的肺尘埃沉着病有12种,即__________、___________________、_________________、________________、_____________、__________________、___________________、_________________、____________________、_________________、_____________________和____________________。
锥形锪孔钻的前角为()度。
A.30
B.0
C.-30
D.-54