振荡频率 : 59 phrases in 16 subjects |
Air defense | 2 |
Automobiles | 2 |
Aviation | 2 |
Construction | 2 |
Earth sciences | 1 |
Electronics | 15 |
General | 1 |
Geophysics | 5 |
Information technology | 1 |
Multimedia | 1 |
Nautical | 1 |
Oil / petroleum | 2 |
Shipbuilding | 1 |
Space | 3 |
Technology | 19 |
Telecommunications | 1 |