A feed window for a feed assembly having at least one primary feed operating at a primary frequency band and at least one secondary feed operating at a secondary frequency band. The nozzle has an exit end that is shaped so as to flare outwardly. When the temperature in the exhaust gas system exceeds a predefinable first value, the heating operating setting is changed over to the basic operating setting. In one embodiment, the underlying benchmark is a U. At least a subset of the plurality of previously-searched questions that can be used to generate a canonical form after removing the one or more specified words are determined. During the moving operation of each developing device to the developing position, the moving distance of at least one developing device differs from the moving distance of the other developing devices.