固 有 频率: 51 phrases in 15 subjects |
Air defense | 2 |
Automobiles | 2 |
Aviation | 5 |
Bridge construction | 2 |
Compressors | 2 |
Electric machinery | 3 |
Engineering geology | 2 |
Hydroelectric power stations | 2 |
Metallurgy | 1 |
Nautical | 6 |
Rail transport | 1 |
Space | 6 |
Technology | 13 |
Telecommunications | 1 |
Wind Energy | 3 |