In $Pheretima$, the number of ring vessels per segment in $12^{\text{th}}$ and $13^{\text{th}}$ segments is: (in $pairs$)

Setae are present in all body segments of the earthworm except in the ..........

What is the typical life span of an Earthworm?

Identify the incorrect statements among the following:
$(a)$ In earthworm,a single male genital pore is present.
$(b)$ Setae help in locomotion of earthworm.
$(c)$ The muscular layer in the body wall of earthworm is made up of only circular muscles.
$(d)$ Typhlosole is a part of the intestine of earthworm.

Which of the following is responsible for destroying bacteria on the body surface of an earthworm?

How many types of nephridia are there? Mention them.