Hearts of Pheretima are situated in the segments

The female genital aperture in earthworm is present ventrally on the segment: (in $^{th}$)

The locomotory organ of an earthworm is ..........

In $Pheretima$,there are red-coloured round bodies in the $4th$,$5th$,and $6th$ segments above the alimentary canal. They are believed to be involved in:

Where does an earthworm store the sperms of its mate?

Match the following columns regarding the types of nephridia in earthworms:

Column-$I$	Column-$II$
$P$. Septal nephridia	$I$. $15^{th}$ segment to the last segment
$Q$. Integumentary nephridia	$II$. $4^{th}, 5^{th}$ and $6^{th}$ segments
$R$. Pharyngeal nephridia	$III$. $3^{rd}$ segment to the last segment