 |
| exhaust smoke: 37 phrases in 15 subjects |
| Architecture | 3 |
| Armored vehicles | 1 |
| Automobiles | 1 |
| Aviation | 1 |
| Construction | 1 |
| Ecology | 11 |
| Engines | 1 |
| Firefighting and fire-control systems | 3 |
| General | 3 |
| Makarov | 1 |
| Military | 2 |
| Technology | 1 |
| Transport | 4 |
| United Nations | 2 |
| Ventilation | 2 |