In an apparatus, a temperature obtainer obtains, in a learning mode of the apparatus during a conductive carrier being deenergized a, value of a carrier temperature based on a physical parameter correlative with the carrier temperature and different from a carrier resistance. The actuator includes a brushed DC motor and a circuit board. Accordingly, relationship information can be carried along with the entity such that database operation can be performed without requirement of additional information from the database. The access point sets a delay time for transmitting a probe response to the probe request depending upon the quality of the link. The top flanges having flange sections which are deformed downwardly to define the profile of the depression while maintaining the continuity of the top flanges as they extend lengthwise of the cross rail. The electrolyte solution for hydrogen generating apparatus according to the invention can increase the time and amount of hydrogen generation by reducing an amount of metal hydroxide generation.