A.0.2m B.0.3m C.0.35m D.0.5m
A.先低壓后高壓、先下層后上層 B.先高壓后低壓、先上層后下層 C.先低壓后高壓、先上層后下層 D.先高壓后低壓、先下層后上層
A.6~7m B.8~9m C.10m D.11m