The Library of Alexandria was probably not destroyed in a single fire.
Why it is true
Contrary to popular belief, the Library of Alexandria did not disappear in a single fire. Historians believe it was lost gradually over centuries, due to funding cuts, wars and various fires, including Julius Caesar's in 48 BC.
Source: Smithsonian
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.