 |
| |||
| 左螺旋; 左侧螺旋桨 | |||
| left screw: 13 phrases in 7 subjects |
| Agriculture | 1 |
| Architecture | 1 |
| Bridge construction | 1 |
| Drilling | 1 |
| Engineering geology | 1 |
| Metallurgy | 1 |
| Technology | 7 |
|
| |||
| 左螺旋; 左侧螺旋桨 | |||
| left screw: 13 phrases in 7 subjects |
| Agriculture | 1 |
| Architecture | 1 |
| Bridge construction | 1 |
| Drilling | 1 |
| Engineering geology | 1 |
| Metallurgy | 1 |
| Technology | 7 |