cellular falls is a sink of matter for room inactivity
cerium_iv_ion is variable_charge_cation. cerium_iii_ion is variable_charge_cation. drop is sphere. droppings is fecal_matter. drop is particle. inapplicability is irrelevance. cell is room. cerium is unalloyed_metal. cellular_compartment is microscopic_object. cellular_compartment is organic_matter.