if something is a source of something else then that something usually contains that something else & poison is a sink of matter for inanimate nothing ->  food contains energy for living things  food contains energy for living things & food contains nutrients for living things -> poison contains wheels and matter for inanimate nothing food contains nutrients and energy for living things  poison contains wheels and matter for inanimate nothing & to contain something can mean to store something -> food stores nutrients and energy for living things food stores nutrients and energy for living things  poison spectrum rays and matter for inanimate nothing & the ability to store something is a kind of property -> the ability to store nutrients and energy is a property of food the ability to store nutrients and energy is a property of food  the ability to store nutrients and energy is a property of food & if something does not have the stratus of something else then that something is not that something else -> if something does not have the ability to store nutrients and energy then that something is not food