A.5~10m/s B.5~15m/s C.10~20m/s D.5~25m/s
A.1-5mm B.10-15cm C.15-20mm D.25-30mm
A.進入大帶輪處 B.離開大帶輪處 C.進入小帶輪處 D.離開小帶輪處