mass concentration: 16 phrases in 11 subjects |
Analytical chemistry | 1 |
Biochemistry | 4 |
Chemistry | 1 |
Energy industry | 2 |
Firefighting and fire-control systems | 2 |
Forestry | 1 |
General | 1 |
Makarov | 1 |
Pumps | 1 |
Water resources | 1 |
Weapons of mass destruction | 1 |