Fill in the blanks:
$(1)$ $.......$ is made using fly ash and slag from the steel industry.
$(2)$ Biogas is used in the production of $.......$ and its byproduct is used as $.......$.

Which of the given statements are correct, when carboxyhaemoglobin reaches $3-4 \%$ in blood?
$(I)$ Leads to headache
$(II)$ Results in cardiovascular problems
$(III)$ Increases the body temperature
$(IV)$ Leads to diarrhoea

Identify the wrong statement among the following:

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.

Environmental pollution is the effect of undesirable changes in the properties of our air,land,water,or soil that may harmfully affect...

Cataract and skin cancer are caused by