 |
| |||
| 管道井 | |||
| 管式工作坑; 管制井筒; 管形井筒; 管身; 管子竖井 (隧道通气孔); 管道竖井; 管道井筒 | |||
| pipe shaft: 10 phrases in 3 subjects |
| Hydroelectric power stations | 8 |
| Nautical | 1 |
| Technology | 1 |
|
| |||
| 管道井 | |||
| 管式工作坑; 管制井筒; 管形井筒; 管身; 管子竖井 (隧道通气孔); 管道竖井; 管道井筒 | |||
| pipe shaft: 10 phrases in 3 subjects |
| Hydroelectric power stations | 8 |
| Nautical | 1 |
| Technology | 1 |