<span>The person needs to report black stools that are tarry. These stools are an indication that there is bleeding. This occurs when digested blood gets in the stool. The stool will smell harshly. A person with a peptic ulcer must report this type of stool immediately.</span>
A) A vaccine is developed that prevents individuals being infected
I assume some of them had fossils in them.
The role of species in an ecosystem, consisting of such things as what it eats, when it eats, and where it lives is niche.