单选题
1分
It should be apparent that little or nothing is gained by opening a drain at the same time as or aft...
It should be apparent that little or nothing is gained by opening a drain at the same time as or after admitting steam. The above sentence probably means ____.
参考答案: D
参考解析: 应确保当蒸汽进入时或进入后,凝水已从放残口全部排空。