 |
| |||
| 自由水面 | |||
| 自由水平［位］ | |||
| 自由水位〔面〕 | |||
| 自由水位; 无压水平面 | |||
| free level: 20 phrases in 12 subjects |
| Aviation | 1 |
| Bridge construction | 1 |
| Electronics | 3 |
| Engineering geology | 3 |
| General | 1 |
| Geophysics | 1 |
| Hydroelectric power stations | 3 |
| Metallurgy | 2 |
| Mining | 1 |
| Oil / petroleum | 2 |
| Space | 1 |
| Technology | 1 |