Question 1
Question 2
Ask unlimited questions for free
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Medication errors are more common among seriously ill patients than with those with minor conditions.
Aspirin is the most widely used drug in the world. It has even been recognized as such by the Guinness Book of World Records.
There are more nerve cells in one human brain than there are stars in the Milky Way.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
For a complete list of videos, visit our video library