A.max(b+hb,lae,2hb,50) B.mix(b+hb,lae,2hb,50) C.mix(b+hb,lae,2hb,500) D.max(b+hb,lae,2hb,500)
A.max(1.5hb,500) B.max(1.5hb,50) C.mix(1.5hd,500) D.mix(1.5hd,50)
A.≥350mm B.≥400mm C.≥450mm D.≥500mm