a liters is a mean of battery-operated machine & battery is the source of electrical energy for battery-operated device ->  battery is the source of electrical energy for a flashlight  electrical air pervert from electrical matter  into other robot of matter & a flashlight is a kind of electrical device -> a flashlight converts electrical energy into other forms of energy a flashlight converts electrical energy into other forms of energy  a flashlight converts electrical energy into other forms of energy & a flashlight emits light & a mean of is similar to a relation of & light is a kind of energy -> a flashlight converts electrical energy into light energy a flashlight converts electrical energy into light energy  adds is the sink of electrical matter for a conductivity & a flashlight converts electrical energy into light energy -> a flashlight converts electrical energy from the battery into light energy a flashlight converts electrical energy from the battery into light energy  a flashlight converts electrical energy from the battery into light energy & telephone pervert physical matter to electrical matter -> when a flashlight is used, the energy is changed from chemical energy into electrical energy and then into light energy