Smog is a combination of:

What are decomposers? Give their role in the ecosystem.

$(a)$ Explain how does burning of fossil fuels cause air pollution?
$(b)$ Justify "Dust is a pollutant".

State whether the following statement is True or False:
All movements of air resulting in diverse atmospheric phenomena are caused by the uneven heating of the atmosphere in different regions of the earth.

$(a)$ Name the two forms of oxygen found in the atmosphere.
$(b)$ Write the biotic and abiotic components of our environment.

$(a)$ Why does the Mathura refinery pose problems to the Taj Mahal?
$(b)$ Why do lichens not occur in Delhi,whereas they commonly grow in Manali or Darjeeling?
$(c)$ What is smog? Mention its harmful effects.