Answer:
The offical defintion of a young womans first period is; menarche
Explanation:
Literally meaning first menstration
That is true
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The answers are, acid rain, respiratory distress, and global warming.
When the skin is exposed to ultraviolet rays, the skin produces a molecule that is turned into Vitamin D.
Sun is the source of ultraviolet rays important for Vitamin D production. Due to this reason, in the case of Vitamin D deficiency, it is recommended by doctor's to absorb sunlight by skin. The Vitamin D production occurs specifically by UV B rays rays which lie in the range of 290-315 nanometer.
The chemical 7-dehydrocholesterol absorbs these rays and convert to previtamin D3. Further, previtamin D3 isomerizes to Vitamin D. Other than sunlight, Vitamin D can be taken through diet. The sources include seafood like fish, fish oil, dairy products, beef liver etc. Vitamin D is required for bone and teeth formation, muscle contraction, immune system etc.
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Answer:
Often by the people that get sick you ask them who they have been around and have video of the people slowly you find them and often a doctor will have some type of evidence that this person had the disease's
Explanation:
