According to the Central Pollution Control Board $(CPCB)$,which size of particulate matter (diameter) is responsible for causing the greatest harm to human health?

Which of the following led to problems like waterlogging and soil salinity?

Eutrophication is the result of

Why is $CNG$ considered a better fuel than diesel/petrol?
$I.$ $CNG$ burns most efficiently without leaving any unburnt remnant behind.
$II.$ $CNG$ is cheaper than petrol or diesel.
$III.$ $CNG$ cannot be siphoned off by thieves and adulterated like petrol or diesel.
Which of the statements given above are correct?

Which one of the following pesticides is banned nowadays?

Biomagnification can be defined as