Ask unlimited questions for free
The word drug comes from the Dutch word droog (meaning "dry"). For centuries, most drugs came from dried plants, hence the name.
Thyroid conditions cause a higher risk of fibromyalgia and chronic fatigue syndrome.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
Asthma cases in Americans are about 75% higher today than they were in 1980.
For a complete list of videos, visit our video library