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When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
Intradermal injections are somewhat difficult to correctly administer because the skin layers are so thin that it is easy to accidentally punch through to the deeper subcutaneous layer.
Limit intake of red meat and dairy products made with whole milk. Choose skim milk, low-fat or fat-free dairy products. Limit fried food. Use healthy oils when cooking.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
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