Must have the ability to sit and stand for extended periods of time; exhibit manual dexterity to dial a telephone, to enter data into a computer, and to perform required tasks; see and read a computer screen and printed material with or without vision aids; hear and understand speech at normal levels, speak in audible tones so that others may understand clearly; physical agility to lift 25 to 50 pounds; to bend, to stoop, to sit on the floor, to climb stairs, to walk and to reach overhead, adeptness and speed in the use of the fingers, hands or limbs in tasks involving close tolerances or limits of accuracy. Assumes responsibility for the opening and closing of the building each school day and for determining, before leaving, that all doors and windows are secured, and all lights, except those left on for safety reasons, are turned off.