oil is a mean of needs units
unit_of_volume is unit_of_measure. unit_of_area is unit_of_measure. unit_of_pressure is unit_of_measure. area_unit is unit_of_measurement. pressure_unit is unit_of_measurement. unit_of_pressure is unit_of_ratio. unit_of_mass is unit_of_measure. unit_of_energy is unit_of_measure. are is area_unit. essential_oil is oil.