World Population Day is
$11^{th} July$
$21^{st} September$
$7^{th} April$
$1^{st} July$
Action of which of the following hormones is blocked during use of $RU\; 486$ (mifepristone)?
Scientificstudy of human population is called
Cause of decline of population in $1927$ was
The bio-index number means