 |
| |||
| 反井从低向高开挖的立井或巷道，其倾斜角小于45° | |||
The server is undergoing maintenance and the site is working in read-only mode. Please check back later.">Add | The server is undergoing maintenance and the site is working in read-only mode. Please check back later.">Report an error
| Get short URL | Language Selection Tips