Which of the following are the respiratory organs of insects?

Which of the following organisms obtain dissolved oxygen from water by diffusion through their body surface during respiration?

In insects,oxygen is carried to different tissues by

Which group of animals respire through lungs?

Explain the structures of respiratory organs for the exchange of gases in various groups/kingdoms of animals.

Among vertebrates,...$A$... use gills whereas reptiles,birds and mammals respire through the ...$B$... Amphibians like frogs can respire through ...$C$... also. Mammals have a well adapted respiratory system. Select appropriate choice for the blanks $A, B$ and $C$ to complete the given $NCERT$ statement.