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Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.
Eating carrots will improve your eyesight. Carrots are high in vitamin A (retinol), which is essential for good vision. It can also be found in milk, cheese, egg yolks, and liver.
Warfarin was developed as a consequence of the study of a strange bleeding disorder that suddenly occurred in cattle on the northern prairies of the United States in the early 1900s.
When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.