Which of the following is responsible for a sound level of $150 \, dB$ or more?

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?

In automobiles,catalytic converters change unburnt hydrocarbons into

Which of the following pesticides are non-biodegradable?

In which one of the following have the $BOD$ (Biochemical Oxygen Demand) of sewage $(S)$,distillery effluent $(DE)$,paper mill effluent $(PE)$,and sugar mill effluent $(SE)$ been arranged in ascending order?

Some effects of sulphur dioxide $(SO_2)$ and its transformation products on plants include: