Answer: C) Romans Explanation: Romans (753 BC - AD 410) began public health and sanitation systems.   Romans established the first public health and sanitation systems by building sewers and aqueducts. They also treated diseases with diet, exercise and meditation.

The word 'Cabinet' is mentioned only once in the Indian Constitution in Article 352(3) which states that "the President shall not issue a proclamation unless the Union Cabinet communicates him in writing that such a proclamation may be issued".

Answer: B) 5 m/h Explanation: As the distance travelled is constant, the time taken is inversely proportional to speed. Let 'u' be the speed of the current and 'v' be the speed of the boat. Speed of the boat downstream = v + u & upstream = v - u => v+u/v-u = 30/20 => v/u = 5 => v = 5u => v + u = 6u = 10/20/60 miles/hr => 6u = 30 m/h => u = 5 m/h

Given that, A+B = 60  and A = 2B. Solving, We get A = 40, B = 20. Five years their ages will be 45 and 25, so the sum of their ages will be 70.

1. Chambal river is infamous for its 'badland'.

2. Elevated land with uneven surfaces located in semi-arid regions, on which sudden heavy rainfall causes rows of deep gullies to form and the entire land becomes rugged. Due to differential erosion, hard and resistant rocks are visible in the form of tall pillars or high flat land above the adjacent land. This land is unsuitable for animal husbandry and agriculture.