A conjoined folding table includes a table plane and plane support frames, wherein under the table plane are disposed two groups of identical support frames. The carbon steel sheet having excellent formability, includes, in wt %, C at 0. An opening in the tubular body allows a user access to the recess. In either of these implementations, we integrate or establish an ad hoc cellular network using mobile ad hoc cellular base stations configured to transmit and receive over a variety of frequencies, protocols, and duplexing schemes. Thereby, a realistic click sensation similar to that obtained when a push-button switch is operated is provided upon operation of the input unit of a pressure type by an operator.