Answer: Three
Reason/Explanation:
The cat, you and the dog are all different populations. Together, there are three populations.
-DustinBR
Ozone, which is also known as trioxygen, is a chemically bonded compound, and contains three oxygens.
An open circulatory system simply
means that the blood flows out of vessels and into the spaces or sinuses. Invertebrates,
insects and crustaceans has an open circulatory system where pump blood goes
into a hemocoel and diffusing back to the circulatory system between cells. In
other animals, the heart pumps the blood into the body cavities, spaces or
sinuses, where the blood surrounds the tissues.
