A.泥土 B.砂粒 C.水藻 D.鋁化合物
A.10-9-10-5 B.10-6-10-5mm C.10-8-10-6mm D.10-9-10-7mm
A.10-4mm以上 B.10-4-10-5mm C.10-5-10-6mm D.10-6-10-7mm