A.無(wú)機(jī)物 B.SVI C.有機(jī)物 D.DO
A.輪蟲(chóng) B.鐘蟲(chóng) C.線蟲(chóng) D.纖蟲(chóng)
A.(10-30)% B.50% C.70% D.90%