 |
| stack gas: 41 phrases in 18 subjects |
| Advertising | 1 |
| Chemical industry | 3 |
| Construction | 2 |
| Ecology | 1 |
| Electronics | 1 |
| Energy industry | 8 |
| General | 3 |
| Metallurgy | 1 |
| Mining | 1 |
| Natural resourses and wildlife conservation | 5 |
| Oil / petroleum | 1 |
| Oil and gas technology | 4 |
| Oilfields | 1 |
| Production | 1 |
| Solar power | 1 |
| Technology | 4 |
| Thermal engineering | 2 |
| Weapons of mass destruction | 1 |