A multi-mode bias modulator operating in envelope tracking mode or average power tracking mode and an envelope tracking power amplifier using the same are disclosed. A video game program executing system executes a video game program. The upper wall has an aperture extending therethrough which defines a drain hole. The landed electroconductive liquid droplet flows along the notch in a thickness direction of the substrate due to an action of a capillary force and reaches assuredly to the individual electrode, thereby electrically connecting the wiring and electrode arranged sandwiching the insulating substrate assuredly. Further disclosed are particular flexible drive shafts which may be used in the tool. The electronic device may be calibrated or recalibrated using the workout template.