A system comprises a first graphics controller adapted to couple to a first display, a second graphics controller adapted to couple to a second display, and a switch through which at least one of communications and power is provided to the second graphics controller. This image forming apparatus controls the bias output of the bias applying section in accordance with information about surface roughness of the transfer medium. In certain embodiments of the method, the strain of Shewanella bacteria is a strain of S. The casement window is simple in structure, low in cost, convenient to install and use, and provides high safety.