Lesley Ratcliffe, age 10, of Toronto, Ontario, Canada, for her question:

What is the secret of the Sphinx?

This story takes us back thousands of years. It was invented by early civilizations that lived around the eastern Mediterranean Sea. The Egyptians, the Greeks and other ancient peoples believed in many legends. One of their legendary characters was the sphinx. This impossible creature was supposed to have the body of a lion, the wings of an eagle and the face of a woman. And their sphinx could talk    or so they claimed. She had a riddle for every traveler who passed by her    and she ate those who failed to give the correct answer.

"What," she asked, "has only one voice, yet walks on four feet, two feet and three feet?" At long last, they say, the Greek hero Oedipus gave the correct answer and the enraged sphinx threw herself into the sea. The simple answer was Man    who crawls through babyhood on four feet, walks upright on two feet through the prime of his life and needs a cane to totter through his aging years.