The secretion of the ceruminous glands forms a: Cerumen with sebum and exfoliated keratinocytes b: Cerumen, which is waterproof c: Cerumen, which traps small insects d: Cerumen, which lubricates the eardrum e: Cerumen, which is a pheromone-like compound

a,b,c,d

Explanation:

Ceruminous glands are the glands that are found in the external auditory canal of the humans.  The ceruminous glands are considered the apocrine glands which secrete cerumen in the external canal of the ear.

The cerumen formed gets mixed with a waxy substance produced by the sebaceous gland called sebum, therefore, is also known as the earwax.

The earwax performs many functions in the ear important of which is that it is involved in the lubrication of the eardrum, acts as a waterproof material, and coat the surface and hair of ear to attach the debris like fungal spores and bacteria to enter the ear.

Thus, a,b,c,d are correct.

answer; both surfaces of the membrane are nonpermeable