Answer:
Absence of a woman's monthly menstrual period is called amenorrhea. Primary amenorrhea is when a girl has not yet started her monthly periods, and she: Has gone through other normal changes that occur during puberty.
I would say hat now is the perfect time because peak bone mass happens at our age. Bone strengthening exercises are always good for your body no matter what, so encourage her/him to do it. I'm guessing the age is about 11-18 maybe...
Hope this helps... mark as Brainliest plz
C. reflex also called Autonomic reflex.
Rain water, underground water and surface water.
