Sandy Meintzer, age 13, of Tucson, Ariz., for the question:

Who printed the first book?

Movable type had to be invented before the first book could be printed. We must give the Chinese credit for making this discovery around 1040 A.D. but so far as we know, they printed no books. Movable type was invented again, this time in Europe, around 1450 in the Rhine Valley. Some experts believe that the complicated invention was developed by many printers working together.

The oldest printed book bearing a date is a Psalter in Latin. The date it bears is August 14, 1457. It also bears the names of the printers Johann Fust and Peter Schoeffer. Most experts, however, believe that there is an even earlier printed book, though it bears no date, This is the famous Bible printed by Johann Gutenberg, perhaps a few years before the Psalter.