A.4.0m B.5.0m C.6.0m D.7.0m
A.4~5個(gè)立桿間距或5~7m B.6~8個(gè)立桿間距或7~9m C.8~10個(gè)立桿間距或8~10m D.2~4個(gè)立桿間距或2~4m
A.200mm B.250mm C.300mm D.350mm