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The NHS lists a number of causes of acne. All of them are systemic, so they will not affect one part of the face more than any other. The basic mechanism is: Acne is caused when tiny holes in the skin, known as hair follicles, become blocked. This is caused by the over-production of sebum, which is not affected by any of the organs listed.


Yes. While there would be no vertical component to pure a pure horizontal velocity vector, direction can be changed via collision with the ground. To some degree it's like banking a billiard ball off of the rail and changing it's direction by 90deg. In the case of a running vertical jump, you were able to change the shape of "the rail" on the fly via your ...

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