Addition of phosphate fertilisers to water bodies causes

What are biodegradable and non-biodegradable pollutants?

Polar stratospheric clouds facilitate the formation of .... .

The part of the Earth where life exists,known as the biosphere,is composed of which components?

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$A$. Sulphate $(> 500 \ ppm)$	$I$. Methemoglobinemia
$B$. Nitrate $(> 50 \ ppm)$	$II$. Brown mottling of teeth
$C$. Lead $(> 50 \ ppb)$	$III$. Laxative effect
$D$. Fluoride $(> 2 \ ppm)$	$IV$. Kidney damage

Choose the correct answer from the options given below.

State whether the following statements are true or false:
$(1)$ Severe respiratory diseases in children are caused by $NO_2$ gas.
$(2)$ Carbon monoxide binds with hemoglobin in the blood to form a carboxyhemoglobin complex.
$(3)$ The carboxyhemoglobin complex is $100$ times more stable than the oxygen-hemoglobin complex.
$(4)$ The $pH$ of rainwater is around $5.6$.