Steve Kirkland, age 13, of Arlington Heights, Ill., for his question:

WHAT IS QUICKSAND?

When water flows underground, it is pushed along under pressure. If the water comes to a low, sandy place, it will flow upward and mix with t.".e sand, making a thick liquid. This, simply, is quicksand. It is denser than ordinary water.

One can float higher in quicksand than in water, but because it is so thick it is hard to move one's arms and legs in it. That's why so many people get frightened when they sink in quicksand.

You'll be interested to know that when a cow sinks into quicksand, it can float for many days with its head and most of its back above water.