|
|
Did you know?
Everyone has one nostril that is larger than the other.
Did you know?
Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.
Did you know?
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
Did you know?
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
Did you know?
The first war in which wide-scale use of anesthetics occurred was the Civil War, and 80% of all wounds were in the extremities.
![The continents were not always in their present positions. The position of the continents is importa](https://biology-forums.com/gallery/47/medium_274477_04_02_15_12_24_34_205791994.jpeg)
![A passenger train crosses Stony Creek Bridge in the Rocky Mountains in 1878. Railroads were importan](https://biology-forums.com/gallery/47/medium_27_24_08_15_1_27_03_22389406.jpeg)
![In countries where water can be contaminated, breastfeeding is an important option for the health of ...](https://biology-forums.com/gallery/47/medium_637842_18_01_17_6_02_51_244931932.png)