 |
| |||
| blowing ventilation; forced ventilation; ventilation by high pressure; descensional ventilation (Katejkin) | |||
| нагнетательное проветривание: 7 phrases in 2 subjects |
| Gold mining | 1 |
| Mining | 6 |
|
| |||
| blowing ventilation; forced ventilation; ventilation by high pressure; descensional ventilation (Katejkin) | |||
| нагнетательное проветривание: 7 phrases in 2 subjects |
| Gold mining | 1 |
| Mining | 6 |