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

Which of the following modes of respiration always continues in a frog?

Match the animals in Column-$I$ with their respiratory surface / organs in Column-$II$ and select the correct option:

Column-$I$	Column-$II$
$A$. Newts and tadpoles	$I$. Plasma membrane
$B$. Platyhelminthes	$II$. External gills
$C$. Reptiles	$III$. Body surface
$D$. Protists	$IV$. Lungs

In crustaceans,respiration takes place by

Match the Column $I$ with Column $II$.

Column $I$ (Animals)	Column $II$ (Respiratory organs / surface)
$1$. Spider	$a$. Internal gills
$2$. Coelenterates	$b$. Book lungs
$3$. Frog	$c$. Plasma membrane
$4$. Fishes	$d$. Lungs
	$e$. External gills

Choose the correct option.

Given below are four matchings of an animal and its kind of respiratory organ:
$I.$ Silver fish - Trachea
$II.$ Scorpion - Book lung
$III.$ Sea squirt - Pharyngeal gills
$IV.$ Dolphin - Skin
The correct matchings are: