For sellers return way or processing time satisfaction?
对卖家处理退货的方式或处理时间满意吗？
The importance for the mine to strengthen the maintenance of the air return way and the points needing attention in designing and allocating the ventilation shaft are pointed out.
同时提出生产矿山加强回风道维护的重要性，以及在设计和布置通风井时应注意的问题。
The importance for the mine to strengthen the maintenance of the air return way and the points needing attention in designing and allocating the ventilation shaft are pointed out.
同时提出生产矿山加强回风道维护的重要性，以及在设计和布置通风井时应注意的问题。
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