Linda Smith, age 12, of Atlanta, Ga.for her question:

What are bacteria?

Bacteria are the smallest members of the plant kingdom, so small that we cannot see them except under a very powerful. microscope. They come in assorted sizes, but on the average they measure about 25,000 to an inch. However, what they lack in size, bacteria make up for in numbers. There is no place on earth where they cannot be found. They rest on every surface, thrive in the oceans and ride on every speck of dust.

A few bacteria are our enemies. We call them germs and they cause certain diseases, Many bacteria are our friends. They help us digest ,. our food, purify our water supplies, help make vinegar, pickles and a host of other food. But most of the bacteria which share our world are neither friends nor enemies. As far as we are concerned they are entirely neutral.