An all-terrain vehicle is supported and driven by endless track units. An apparatus may include an interconnect, a set of pads, a set of isolation circuits, and a test circuit. The energy charging-discharging unit is coupled between the first bridge and the second bridge arm units. The biasing force of the spring is received by a wide contacting surface of the supporting member, thereby reducing abrasion wear of the contacting surface. The solvent and collected stool is homogenized into a mixture which is then filtered by a multi-stage filter system to create a solution containing microflora in the desired consistency. The polyimide polymer of the present invention is developable in an aqueous alkaline solution, and has the properties associated with an insulating layer and photoresist.