|
|
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
Blood is approximately twice as thick as water because of the cells and other components found in it.
Serum cholesterol testing in adults is recommended every 1 to 5 years. People with diabetes and a family history of high cholesterol should be tested even more frequently.
The horizontal fraction bar was introduced by the Arabs.
Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.