Sharks are older than trees.
Why it is true
Sharks have swum in the oceans for 400 million years, while the first trees appeared 350 million years ago.
Source: Evolutionary Biology
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.