Assertion: Excess of nitrates in drinking water is harmful for infants.
Reason: Nitrates are responsible for blue baby syndrome.

Give scientific reasons: Noise is also considered a part of air pollution.

The cause of decline in the population of reptiles and birds is

Why is $CNG$ considered a better fuel than diesel?
$(a)$ It cannot be adulterated.
$(b)$ It takes less time to fill the fuel tank.
$(c)$ It burns more efficiently.
$(d)$ It is cheaper.
$(e)$ It is less inflammable.
Choose the most appropriate answer from the options given below:

The pollutants emitted by jet aeroplanes in the outer atmosphere,such as fluorocarbons,are known as:

Catalytic converters:
$I.$ These are fitted into automobiles for reducing emission of poisonous gases like $NO_x$ and $CO$.
$II.$ They have expensive metals like platinum,palladium,and rhodium as catalysts.
$III.$ As the exhaust emission passes through the catalytic converter,nitric oxide splits into nitrogen and oxygen; carbon monoxide is oxidized to carbon dioxide,and unburnt hydrocarbons are burnt completely into $CO_2$ and $H_2O$.
$IV.$ Motor vehicles fitted with catalytic converters should use unleaded petrol because lead in the petrol inactivates the catalyst.
Which of the statements given above are correct about catalytic converters?