Linda Moynihan., age 12, of Jamestown, N. Y., for her question:

Why does a sea shell roar?

A flat clam shell has nothing to say, But if you hold a coiled, conch‑shaped shell to your ear you can hear the roar of the distant ocean ‑ or so they say, Actually, of course, the shell does not roar by itself. It needs the beating of your heart to make a sound.

The inside of the shell is an intricate series of chambers, just right for making echoes. The throbbing sound of your heart beat becomes trapped in the shells and its echo bounces back from the hard walls with a sound like the pounding of ocean waves,