Which causes a drop in female hormone levels?

the onset of the menstrual flow

if an egg is released from the ovary

if the uterine wall thickens

if the egg is not fertilized

I will give brainliest

True but only in the south coastal areas during september and early october.

Air enters through the nose (and sometimes the mouth), moves through the nasal cavity, the  pharynx, the  larynx, enters the  trachea, moves through the  bronchi  andbronchioles  till the alveoli.