<h3><u>Answer;</u></h3>
A. Gas exchanges takes place by diffusion.
B. It is an open system.
<h3><u>Explanation</u>;</h3>
- Most molluscs and arthropods have an open type of circulatory system.
- Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells.
- Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.
The correct answer is C A single-celled protist divides into two cells, and each one becomes another protist.
The remains of a Hadrosaur are an example of a fossil typically structures like bones shells and teeth fossilized more often then things like tissues or plant leaves.