In crustaceans,respiration occurs through ..........

Match the following columns:

Column-$I$ (Organisms)	Column-$II$ (Respiratory Organs)
$P$. Fishes	$I$. Lungs
$Q$. Reptiles,Birds,Mammals	$II$. Gills
$R$. Amphibians like frogs	$III$. Lungs and moist skin

$O_{2}$ exchange with $CO_{2}$ by simple diffusion over the entire body surface takes place in:
$I.$ Sponges
$II.$ Coelenterates
$III.$ Flatworms
Select the correct option to complete the given statement.

Match the Column $I$ with Column $II$ and select the correct option:

Column $I$ (Animals)	Column $II$ (Respiratory organs)
$i$. Sponges	$a$. External gills
$ii$. Insects	$b$. Plasma membrane
$iii$. Limulus	$c$. Tracheae
$iv$. Amphibian tadpoles	$d$. Book gills

In the lower order of invertebrate animals,how does the respiration process take place?

Skin is an accessory organ of respiration in