The main cause of air pollution in large cities is ........

What does the troposphere contain?

Match the following metals in drinking water with their maximum prescribed concentration in $ppm$:

List-$I$ (Metal)	List-$II$ (Concentration in $ppm$)
$A$. $Mn$	$I$. $0.05$
$B$. $Zn$	$II$. $5.0$
$C$. $Cd$	$III$. $0.005$
$D$. $Cu$	$IV$. $3.0$

Provide the correct statement for the following: (Use $T$ for True and $F$ for False statements.) $(1)$ Plants obtain elements like carbon,hydrogen,and oxygen from air and water. $(2)$ Plants obtain elements like $N, P, K, Ca$ from the soil. $(3)$ Compound fertilizers contain nitrogen as ammonium nitrate,phosphorus as $PCl_3$,and potassium as $KO_2$. $(4)$ The use of $NPK$ fertilizers increases the production of crops and vegetables in the soil.

Give the examples of particulate pollutants.

What is meant by environmental pollution?