![](https://static.youtibao.com/asksite/comm/h5/images/m_q_title.png)
[单选题]
高炉长期休风用N2气作稀释和置换介质后,要用空气将N2驱除,当系统内O2和CO达到多少为合格?()
A.﹥20.5%,﹤40mg/m3
B.﹥20.8%,﹤35mg/m3
C.﹥20.2%,﹤25mg/m3
D.﹥20.6%,﹤30mg/m3
查看答案
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)
A.﹥20.5%,﹤40mg/m3
B.﹥20.8%,﹤35mg/m3
C.﹥20.2%,﹤25mg/m3
D.﹥20.6%,﹤30mg/m3
A.发生着火后,可将打开的风口视孔盖关上几个
B.发生着火后,不必打开的风口视孔盖关上几个
C.可检查高炉煤气切断阀是否关严
D.可检查高炉冷却设备是否漏水