Answer #14 and will mark brainliest

the one in 2016 is smaller so it doesn't have as much room for animals

Explanation:

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link:

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.