 |
| |||
| sand filter; slow filter; retarded filter | |||
| low-rate trickling filter (в водоснабжении); standard trickling filter (в водоснабжении) | |||
| slow sand filter (water treatment) | |||
| low-rate filter; standard-rate filter | |||
| low-rate trickling filter | |||
| медленный фильтр: 3 phrases in 2 subjects |
| Ecology | 2 |
| Makarov | 1 |