Just under two-fifths of Americans have a valid one of these. If you don’t have one, it’ll prevent you from doing something. What is it?

Just under two-fifths of Americans have a valid one of these. If you don’t have one, it’ll prevent you from doing something. What is it?

Just under two-fifths of Americans have a valid one of these. If you don’t have one, it’ll prevent you from doing something. What is it?

Ans: A passport.