Duffy Cowan, age 10, of Sylva, N.C., for his question:

HOW IS COFFEE DECAFFEINATED?

Coffee is certainly one of the world's favorite adult drinks, and it has been in the news lately because of its cost. Coffee plants are grown today in many parts of'the world including South America.

Some people can't drink coffee because of an allergy to caffeine, the principal stimulant found in the beverage. For them there is decaffeinated coffee, processed by softening the green beans with steam under pressure, and then extracting the caffeine by applying benzol or alcohol. After the caffeine has been removed by resteaming, the coffee beans are roasted and treated in the same way as regular coffee.