Complete to two case studies below using pages 36-37 which describe human modification

The human body is modified with the environmental needs.

Explanation:

A human body is exposed to its environment. There are body enzymes which reacts together to adjust in a certain environment. People living in polluted area are used to of that pollution. They drink polluted water, breathe in polluted air and are still alive but when someone from other area visits such environment, they fall ill and cannot survive in that polluted environment. This is entirely because their body refuses to accept the new changes in environment quickly.