Earthworms increase the . . . . . . of the soil.

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

In which of the following are $Chloragogen$ cells found?

In earthworms,salivary glands are found in the .........

The main function of the clitellum is:

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.