Answer:
1.) Why does menstruation begin?
A.) Period happens because of changes in hormones in the body.
2.) How long does the menstrual cycle usually last?
A.) the menstrual cycle lasts 21 to 35 days while bleeding between 2 to 7 days
<u>-TheUnknownScientist</u>
Answer:
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Explanation:
Bohr's model of the atom states that electrons orbit an atom's nucleus in electron shells of increasing energy. ... Thomson's model, or the plum pudding model, it describes atoms as spheres of positively charged matter, in which electrons are embedded in
C. Wind, is NOT a biotic factor of a niche. Hope this helps!