The range of diameter of cast iron sewer is __________
(a) 20-100mm
(b) 150-750mm
(c) 40-250mm
(d) 100-250mm
This question was addressed to me in a national level competition.
The above asked question is from Material for Sewers in portion Construction of Sewers, Sewer Appurtenances and Sewage Pumping of Environmental Engineering