Answer the follow

i. Gaseous fuel- methane can be obtained by microbial anaerobic decomposition of urban agricultural and industrial waste.

ii. Ethanol, an alcohol is a clean (smokeless) fuel obtained during fermentation of molasses by the yeast- Saccharomyces.

iii. Hydrogen gas is considered to be the fuel of future. Hydrogen gas is released during bio-photolysis of water in which bacteria perform the photo-reduction.

It is necessary to increase the use of these fuels so that the fuels that are obtained from the non-renewable energy sources can be conserved. Also, air pollution can be reduced.