Question 1
Question 2
Ask unlimited questions for free
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
The strongest synthetic topical retinoid drug available, tazarotene, is used to treat sun-damaged skin, acne, and psoriasis.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
There are approximately 3 million unintended pregnancies in the United States each year.
The first war in which wide-scale use of anesthetics occurred was the Civil War, and 80% of all wounds were in the extremities.
For a complete list of videos, visit our video library