Among the gases $(a)-(e)$,the gases that cause greenhouse effect are
$(a) CO_2$; $(b) H_2O$; $(c) CFCs$; $(d) O_2$; $(e) O_3$

Given below are two statements :
Statement $I :$ The $pH$ of rain water is normally $\sim 5.6$.
Statement $II :$ If the $pH$ of rain water drops below $5.6,$ it is called acid rain.
In the light of the above statements,choose the correct answer from the options given below:

Given below are two statements :-
Statement $I :$ The value of the parameter "Biochemical Oxygen Demand $(BOD)$" is important for survival of aquatic life.
Statement $II :$ The optimum value of $BOD$ is $6.5 \ ppm$.
In the light of the above statements,choose the most appropriate answer from the options given below:

Mention the types of atmospheric pollution.

Which of the following is a lung irritant that can lead to an acute respiratory disease in children?

How much oxygen is added to the atmosphere annually at the end of the process of photosynthesis?