Terminal bronchioles subdivide into microscopic branches called bronchioles.

The terminal bronchioles subdivide into microscopic branches called respiratory bronchioles.
Bronchioles, one f the important part of our respiratory system. we inhale air an that air passes through the nose and mouth, it is drawn into trachea and then goes to main bronchus. Directing air to the alveoli, is the function of respiratory bronchioles.

There is sand and mud

1. aspect is nothing really because the answer is right in front of your face