B. 25 years(Correct)
C. 50 years
D. 75 years
Sewerage system is usually designed for_________________?
B. 25 years(Correct)
C. 50 years
D. 75 years
B. 25 years(Correct)
C. 50 years
D. 75 years
B. 25 years(Correct)
C. 50 years
D. 75 years
B. 25 years(Correct)
C. 50 years
D. 75 years