The cartilages present in the larynx of a rabbit are:

What is the function of the epiglottis?

What is the length and diameter of the trachea?

The nerve related with the diaphragm is:

Which structure in mammals does not help in respiration?

Identify the component of the respiratory system which displays the features given below and choose the correct option:
$I.$ Double layered
$II.$ Fluid contained in it reduces the friction on the lung surface
$III.$ Its outer layer is in contact with the thoracic wall
$IV.$ Its inner layer is in contact with the lungs