The present invention discloses a kind of electronic organ with free-combined keys and the method to realize free combination of key groups. A polyphenylene ether is reacted with a capping agent in a solvent to form the polyphenylene ether resin containing residual aliphatic unsaturation, which is precipitated from solution by combining the solution with an antisolvent. When receiving a user instruction for reduction up an image to be displayed on a display section, the control section selects from the memory either the original image data or a plurality of reduced image data stored therein based on an image enlargement ratio and the size of display image data for output to the display section. The optical coupling member is arranged so that wave fronts of the terahertz waves generated from the waveguides are matched together. The patient valve also has a passage extending from the atmosphere to the interior thereof adjacent to the one-way valve member and upstream thereof through which medication can be injected into the air as it passes from the bag to the one-way valve member.