进料切除后，保持开工炉热氮气量不低于（）Nm3/h。
参考答案：45000
二个物体的质量之比为2:3，密度之比为1:2，则两个物体的体积比为[ ]
A.4:3
B.3:4
C.1:3
D.3:1
In relation to the issuing of company shares explain:
(c) bonus issues. (4 marks)
