How is an organ formed?

$Pheretima$ $posthuma$ and $Periplaneta$ are similar in which aspect?

What do tissues combine to form?

Which gland in mammals secretes odoriferous substances?

How many of the given statements are true?
$A.$ The dry surface of the skin and the moist surface of the buccal cavity are lined by compound epithelium.
$B.$ Cuboidal epithelium facilitates diffusion across the epithelium.
$C.$ Intercalated discs are the cell junctions between the cardiac muscle cells.
$D.$ Skeletal muscle fibers can be located in the biceps muscle.
$E.$ In a bone,osteocytes are located in lacunae.

Match the terms in column $I$ with those in column $II$:

Column $I$	Column $II$
$(a)$ Compound epithelium	$(i)$ Alimentary canal
$(b)$ Compound eye	$(ii)$ Cockroach
$(c)$ Septal nephridia	$(iii)$ Skin
$(d)$ Open circulatory system	$(iv)$ Mosaic vision
$(e)$ Typhlosole	$(v)$ Earthworm
$(f)$ Osteocytes	$(vi)$ Phallomere
$(g)$ Genitalia	$(vii)$ Bone