Why is $CNG$ better than diesel?

Photochemical smog formed in congested metropolitan cities mainly consists of

Consider the following statements:
$(a)$. $40\%$ of the forest has been lost in the tropics.
$(b)$. $JFM$ was introduced in $1965$ by the $UNCED$.
$(c)$. The Bishnoi community belongs to Odisha and played a major role in the conservation of forests.
$(d)$. The Chipko movement started in the Garhwal Himalayas.

Which of the following statements is correct?

What is the effect of an algal bloom in a lake?

Arrange the following in increasing order of their $BOD$ values: Sewage $(S)$,Distillery Effluent $(DE)$,Paper Mill Effluent $(PE)$,and Sugar Mill Effluent $(SE)$.