The diaphragm muscle sits below the lungs and continuously expands and contracts. What happens in the chest cavity as a result of this expansion and contraction? O The body fills with carbon dioxide.
O A change in air pressure occurs.
O The alveoli fill with oxygen.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

this is more of a statement than a question. is there answers to go along with this, or is it opinion based?