Approximately how long does the menstrual cycle last if fertilization does not take place?.

because of

it’s lava came from an explosive eruption

atp is used for energy.

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.