The removal of floating and suspended solids from sewage through filtration and sedimentation is the part of
Primary treatment
Secondary treatment
Tertiary treatment
Biological treatment
Which of the following is not an organo-chlorine
Cork is obtained from
Triazines are derived from
$A$ : Barley, Sorghum and millet are smoother crops.
$R$ : They favour the growth of some common weeds.
Which of the following pesticides does not inhibit cholinesterase