The bronchi (singular: bronchus) are the airways that lead from the trachea into the lungs, and then branch into smaller bronchioles. Structurally, the bronchi are made up of cartilage that gives them stability and prevents their collapse.
Functional and economically most important mineral in nutrition of layers
is calcium, primary because of egg production, i.e. forming of the egg shell.
The largest taxon is the Domain and the smallest is the species.
The answer is elevation :)
All of these are necessary