A.50%-60% B.60%-70% C.60%-80% D.70%-80%
A.沼澤土 B.棕壤 C.潮土 D.風(fēng)沙土
A.砂質(zhì)土>壤質(zhì)土>黏質(zhì)土 B.壤質(zhì)土>砂質(zhì)土>黏質(zhì)土 C.黏質(zhì)土>壤質(zhì)土>沙質(zhì)土 D.壤質(zhì)土>黏質(zhì)>土砂質(zhì)土