MCQOPTIONS
Saved Bookmarks
| 1. |
Inter-distance between ventilation columns in a sewer line is kept |
| A. | 25 to 50 m |
| B. | 50 m to 100 m |
| C. | 100 m to 150 m |
| D. | 150 m to 300 m. |
| Answer» E. | |