A flame-retardant laminate 10 having a substrate 11 and a print-image-receiving layer 12 stacked on the substrate 11, is characterized in that the substrate 11 has a flame resistance equivalent to VTM-0; and the print-image-receiving layer 12 contains a resin and titanium oxide and no halide; exhibits a percent mass retention of 50% or higher as determined at 600\xb0 C. A passage is disposed on the tractor body for allowing the driver to move past the driver’s seat between the tractor control station and the implement control station. The second unit has a first end and a second end, and the first end of the second unit rotatably connects to the first unit. A feedback unit detects an electrical signal from the transformer and supplies the detected electrical signal to the inverter controller, and an initial operation controller controls an intensity of the electrical signal supplied to the inverter controller from the feedback unit. The multiple grinding wheel is mounted in a grinding spindle.