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The strongest synthetic topical retinoid drug available, tazarotene, is used to treat sun-damaged skin, acne, and psoriasis.
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
Blood is approximately twice as thick as water because of the cells and other components found in it.
Urine turns bright yellow if larger than normal amounts of certain substances are consumed; one of these substances is asparagus.
The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.
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