2nd I'm pretty sure. it would truly be correct if it were italicized to
Females it begins prior to birth, while in males, it begins after birth.

QUESTION:- The sun shinning on thr surface of a lake can heat up the air just above the water.What happens if this air gets warmer then the air above it?
ANSWER:- If the air gets warmer then the aur above it then the air will go above then the air above on it .
REASON :- It is a rule of wind that it flows from hidh density to low density.
HOPE IT HELPS YOU.
Answer:
because when it gets cold, it weakens our immune system and we become more vulnerable to sickness