A.先換質(zhì)位,在用對(duì)當(dāng)關(guān)系 B.換位質(zhì) C.先換位質(zhì),再用對(duì)當(dāng)關(guān)系推理 D.先換位,再用對(duì)當(dāng)關(guān)系推理