The diagram below represents a magnified view of an air sac in the human lung. The white arrows indicate blood flow. Which two systems are interacting in this diagram.

Breathing is a process that

i) provides ${\mathrm{O}}_2$ to the body.

ii) breaks down food to release energy.

iii) helps the body to get rid of ${\mathrm{CO}}_2$.

iv) produces water in the cells.

Which of the following gives the correct combination of functions of breathing?

Pick the odd one out.

The figure shows a diagrammatic view of the human respiratory system with labels A, B, C and D. Select the option which gives correct identification and main function and/or characteristic.

Match the following and mark the correct options.

The below diagram shows the respiratory system of human beings.

Identify the correct function of the part labelled as 'X'.