People who work in large office building get sick more often than normal. They may have headaches,stomachaches, or sore, red skin. The reason for this lies in the buildings themselves. These large building usually have windows that cannot be opend. The same air stays in the building for a long time and becomes unhealthy. It may be full of chemicals that come from the furniture,the rugs,or the photocopy machines. Or it may be full of cigarette smoke. This unhealthy air causes "sick building syndrome," as doctor call this problerm. It order to cure the people with this syndrome, it is necessary to treat the building. The answer is simple:more fresh air.