This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Air, Light, Sound, Housing, Radiation, Waste Disposal, Subject name: Social & Preventive Medicine
The amount of sewage flowing in a system in 24 hrs is called: 
Select and explain. 
A. Sewage rate, B. Dry weather flow, C. RCA index, D. Sludge
B: Dry weather flow
Answer: B: Dry weather flow 
Explanation: Sewage: is waste water from a community, containing solid and liquid excreta, derived from houses, street and yard washings, factories and industries Composition of sewage: 99.9% water + 0.1% solids (organic & inorganic) Dry weather flow : is the average amount of sewage that flows in sewerage system in 24 hrs Strengths of sewage is expressed in terms of: Biological oxygen demand (BOD), Chemical oxygen demand (COD), Suspended solids.