[Solved] According to Piaget, the concepts of reversibility and conservation develop during the __________ stage. Microscopic Blood: Blood present in such small quantities that it is not visible to the naked eye but can be detected through microscopy or chemical tests. Chemical Spray: A dispersion of chemical substances in a fine spray form, often used for cleaning, disinfection, or pest control. Pathologic Examination: The study and analysis of body tissues and fluids to diagnose disease or medical conditions. Good Lighting: The quality of light in a space that makes it easy to see and contributes positively to the environment's atmosphere.