Changes that make a species better able to live in new areas are

Changes that make a species better able to live in new areas are adaptation.

Explanation: Adaptation is the most important and necessary phenomenon of evolution. It includes various changes in species. These changes make organism fittest for the changed environment conditions. By which organisms become able to survive in the new environment. Adaptation is always significant for the organisms.

Example : Migration is the most common example of adaptation. Seen in birds.

"d.) carbon dioxide and hydrogen sulfide"

helicase, i think thats it