The sinuses are O air-filled cavities that secrete mucus to keep the nose moist and remove bacteria.
O tubes at the end of the pharynx that are made of different types of cartilage and muscle, and lined with a mucous
membrane.
tubes that conduct air to the lungs, and allow for gas exchange of oxygen and carbon dioxide.
small, curved, bony plates that line the walls of the nasal cavity, and are covered with a mucous membrane.

O air-filled cavities that secrete mucus to keep the nose moist and remove bacteria.

answer: because barriers look like ball

explanation: there round and blue like my ball

the aorta is the large artery leaving the heart branches into smaller arteries, which eventually branch into capillaries.the arteries carry oxygen and nutrients away from your heart, to your body's tissues. the capillaries are small, thin blood vessels that connect the arteries and the veins. the statement that arteries carry oxygen-rich blood to capillaries is true. veins on the other hand are blood vessels that take oxygen-poor blood back to the heart.