air-cleaning : 61 phrases in 23 subjects |
Agriculture | 1 |
Agronomy | 1 |
Automobiles | 1 |
Construction | 5 |
Drilling | 2 |
Ecology | 7 |
Electrical engineering | 1 |
Electronics | 2 |
Energy industry | 6 |
Makarov | 7 |
Metallurgy | 1 |
Microelectronics | 1 |
Mining | 2 |
Natural resourses and wildlife conservation | 2 |
Nautical | 2 |
Nuclear and fusion power | 1 |
Nuclear physics | 3 |
Oil / petroleum | 2 |
Oil and gas | 2 |
Oilfields | 1 |
Polygraphy | 1 |
Technology | 8 |
Transport | 2 |