About composition of water and organisms that lives there.
Explanation:
scientists might be able to learn about the composition of seawater that was present millions of years ago if we study those stones that comes in contact to that ancient seawater because the traces of particles still present on it. This study provides valuable information about ancient times of earth and its natural resources. These rocks also provides animals that were present in that sea water at that time.
I think the answer is {b.false} Infectious diseases are diseases that spread from one person to other either directly or indirectly. I think this is the answer.
