Dust, water, and scratches are enemies of the microscope because they can affect the clarity of the image produced by the microscope. Dust particles can obstruct the path of light, leading to a blurry image. Water can cause damage to the delicate components of the microscope, such as the lenses and electrical parts. Scratches on the lenses can distort the image and reduce the overall quality of the microscope's performance. Therefore, it is essential to keep the microscope clean, dry, and free from any potential sources of damage like dust, water, and scratches.