Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
The largest breed of rabbit is the Flemish Giant.
65
The 409 escalators in the London subway cover a distance every week which is approximately equivalent to several trips around the globe!
94
Your thumb is about the same size as your nose.
124
Your body is creating and killing about 2.4 million red blood cells per second.
17