引人线 : 28 phrases in 14 subjects |
Air defense | 1 |
Architecture | 3 |
Aviation | 1 |
Communications | 1 |
Construction | 1 |
Electronics | 6 |
Explosives and Explosive Ordnance Disposal | 1 |
General | 2 |
Metallurgy | 1 |
Rail transport | 3 |
Refrigeration | 1 |
Shipbuilding | 1 |
Technology | 3 |
Telecommunications | 3 |