Shakti along with his parents was going to the reilway station by an auto to catch a train. Shakti's father was recollecting his childhood days and said that in those days, autos were run with petrol only. His mother added that diesel was used to run autos in later days. Shakthi said that nowadays, autos are preferably run with CNG, Shakti questioned his father regarding the advantage of CNG over petrol and diesel. What was his father's explanation ?

Explanation

CNG does not produce any harmful gas, and thus, it reduces the maintenance cost and it is a clean fuel. While petrol and diesel contain N and S which upon combustion produce `NO_2` and `SO_2` , respectively. These lead to acid rain. Hence, CNG can be a substitute for petrol and diesel.