Besides mammals,diaphragm also occurs in

What is the epiglottis made of?

What is the number of tracheal cartilaginous rings in humans?

The cartilages present in the larynx of a rabbit are:

Analogy type questions:
$(1)$ Sponges,Coelenterates : Respiration through entire body surface :: Insects : ....
$(2)$ Larynx : Cartilaginous box :: Epiglottis : .......

The trachea divides into left and right primary bronchi at the level of $-$