Q.

After cleaning a slow sand filter, the filtered water is not used for

A. 6 hours to 12 hours
B. 12 hours to 18 hours
C. 18 hours to 24 hours
D. 24 hours to 36 hours
Answer» D. 24 hours to 36 hours
3.8k
0
Do you find this helpful?
22

Discussion

No comments yet