Air pollutants:
$I.$ Cause injury to all living organisms.
$II.$ Reduce growth and yield of crops and cause premature death of plants.
$III.$ Affect the respiratory system of humans and animals.
Which of the statements given above are correct?

For $3$ wheelers vehicles,which emission norm was implemented throughout the country since October $2010$?

Given below are two statements:
Statement $I:$ In a scrubber,the exhaust from the thermal plant is passed through a spray of water or lime to remove gases like $SO_2$.
Statement $II:$ Particulate matter $(PM\,2.5)$ cannot be removed by a scrubber but can be removed by an electrostatic precipitator.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which of the following metals is a water pollutant and causes sterility in human beings?

$2$-wheelers Bharat Stage-$III$ $(BS-III)$ norms were implemented throughout the country in:

Noise is: