The depletion of ozone in Antarctica is caused by the formation of which of the following substances?

What is responsible for soil pollution?

Which one of the following statements is not correct?

Some statements are given:
$(S_1) \ CO_2$ is a greenhouse gas.
$(S_2)$ Classical smog contains smoke,fog,and a high concentration of $SO_2$.
$(S_3) \ DDT$ is biodegradable.
$(S_4)$ Drinking water should have a high $B.O.D.$
Which is the correct sequence of true $(T)$ or false $(F)$ regarding the above statements?

Summarize the international standards for the concentration of various metals and ions in drinking water.

Which one of the following is not a common component of Photochemical smog?