Ahmed Khan developed a method to create roads by mixing polyblend and bitumen. The life of the roads constructed in this manner increased by a factor of $................$.

The most densely populated city in India is

Match the items in Column $A$ with those in Column $B$:
\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau

Column $A$	Column $B$
$(A)$ Catalytic converter	$(i)$ Particulate matter
$(B)$ Electrostatic precipitator	$(ii)$ Carbon monoxide and nitrogen oxides
$(C)$ Earmuffs	$(iii)$ High noise level
$(D)$ Landfills	$(iv)$ Solid waste

Which of the following problems is not caused by noise pollution?

The quantity of $CO_2$ in the atmosphere is about (in $\%$)

Which of the following is an inexhaustible resource?