The human body has about 60,000 km of nerves.
Why it is true
The human nervous system is a vast network connecting the brain to all parts of the body.
Source: Neuroscience
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.