If an earthworm is kept in $40\%$ $KOH$ for a long time,which part remains insoluble?

Explain the nephridia of an earthworm.

Identify the correct sequence of organs in the digestive system of an earthworm.

Which of the following correctly describes the location of body parts in the earthworm Pheretima?

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

Which of the following animal's sensory system does not have eyes but does possess light and touch sensitive organs (receptor cells) to distinguish the light intensities and to feel the vibrations in the ground?