$3, 4-$ benzopyrene causes:

Which of the following is normally not an atmospheric pollutant?

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?

Give scientific reasons: The use of $CNG$ is more advantageous than the use of petrol.

What is the intensity of sound in normal conversation?

Particulate matter with a diameter of $2.5$ micrometres or less and a sound level of $150$ $dB$ or more causes the greatest harm to human health.