The invention relates to a light prefabricated module which is made from natural reed and which can be used in construction as a versatile and easy-to-handle structural element. The water-soluble interjacent complex forms a solution in water that is free of insoluble polymer particles. More specifically, the base body is provided by press-molding a steel sheet and the base reinforcing part is provided by press-molding a steel sheet or is provided as a reinforcing plate separately attached to an outer surface of the base body, and the base structure further includes a reinforcing part processing member additionally provided in the reinforcing plate. These steps can be performed using each of the wordlines of a selected range of the DRAM array or all of the DRAM array so as to erase the data stored in the selected range or in all of the DRAM array. A second switch circuit connects the first switch circuit and the second input terminals.