Described herein are processes and devices that determine and assign rewards as a group in a wagering game system utilizing social contacts. A voltage monitoring circuit is connected to the individual fuel cells forming a fuel cell stack. A latch circuit fetches the digital picture signal in synchronization with making the output of the scanning circuit active. Thereafter, dielectric spacers are formed on sidewalls of the gate electrode. A handle is connected to an upper end of the shaft body. Therefore, according to the different relevancy search results, readers can obtain different relevant information for the ebook currently displayed.