什么情况下严禁工电部门检修作业？
参考答案：
对处于闭塞状态的闭塞设备和办理进路后处于锁闭状态的信号、联锁设备，严禁进行检修作业。
Following recent reports about a ripener used in several provinces, experts said the chemical
_____ ripens fruits and vegetables does no harm to human health.[ ]
A. who
B. that
C. why
D. how
当发生8224型给煤机断煤时，应如何进行处理？
