Answer:
a layer or a series of layers of rock in the ground. ,
a level or class to which people are assigned according to their social status, education, or income.
Explanation:
Biology overlaps with chemistry in studying the structure and functions of activities at the molecular level. The principles of chemistry are useful in cell biology because all living cells consist of chemicals and various chemical processes take place in many living organisms.
The 4th one. Maintaining body temperature and cooling down