A rain sanitary sewer is constructed to carry_________________ ?

A. Running expenses
B. Maintenance expenses
C. Operation expenses
D. All the above

A. Degradation
B. Active decomposition
C. Recovery
D. Cleaner water

A. 3 ppm
B. 4 ppm
C. 5 ppm
D. 10 ppm

A. 5
B. 10
C. 15
D. 20

A. 50 m
B. 100 m
C. 200 m
D. 300 m