A.磷 B.碳 C.硫 D.鉀
A.0.5~0.7℃ B.0.3~0.5℃ C.0.5~0.6℃ D.0.4~0.7℃
A.種間競(jìng)爭(zhēng) B.種內(nèi)競(jìng)爭(zhēng) C.個(gè)體競(jìng)爭(zhēng) D.競(jìng)爭(zhēng)