The purpose of a) _____ is to remove the contaminated air and to introduce the
fresh air, to provide a sufficient quantity of air for b) _____.
In large mines natural ventilation is not sufficient, and the air current has to be
assisted by c) _____. This especially refers to coal mines and to mines where methane or
carbon dioxide penetrate into the workings and where much d) _____ is produced.
The function of the fun is to increase the flow of e) _____ through the mine airways
overcoming the resistance of the workings and inertia of the air. A mine ventilated in this
way must obviously have two openings, so that the air current may enter in one place, flow
through the mine and leave the mine by the second f) _____. Thus, mines with artificial
ventilation must have at least two shafts, one to act as a downcast, and the other as the
upcast.
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Ответы
The purpose of a) ventilation is to remove the contaminated air and to introduce the fresh air, to provide a sufficient quantity of air for b) **respiration**.
In large mines, natural ventilation is not sufficient, and the air current has to be assisted by c) fans. This especially refers to coal mines and to mines where methane or carbon dioxide penetrate into the workings and where much d) quantity is produced.
The function of the fan is to increase the flow of e) ventilation through the mine airways, overcoming the resistance of the workings and inertia of the air. A mine ventilated in this way must obviously have two openings, so that the air current may enter in one place, flow through the mine, and leave the mine by the second f) ventilation. Thus, mines with artificial ventilation must have at least two shafts, one to act as a downcast, and the other as the upcast.