A display apparatus including a main body, a display panel installed in the main body, a video call unit installed to the main body, a circuit board for control of the video call unit, and a cable to connect the video call unit and the circuit board to each other, is provided. Desirably, the seat post assembly is configured to be supported by a bicycle frame and is configured to support a bicycle seat on its upper end. A controller is included that causes a vehicle to selectively run in a variety of run modes that differ in states of operation with respect to at least one of the drive power sources. , using a URL scheme that is native to the computer to forward the non-native transport. The peripheral cores have Bragg gratings and are peripherally positioned in the cladding with respect to the neutral planes. The stripping solution of the invention assures effective protection of Al, Cu and other wiring metal conductors against corroding as well as efficient stripping of the photoresist film, post-ashing residues such as modified photoresist film and metal depositions.