{$mEDiAurl} whAt tEChniquE DoEs thE proFEssor usE to EnCourAgE stuDEnt DisCussion A、hE givEs stuDEnts positivE rEinForCEmEnt By prAising thEir EFForts. B、hE Asks thE stuDEnts to tAlk Among thEmsElvEs in smAll groups. C、hE Assigns A DiFFErEnt pArt oF thE tExtBook to EACh stuDEnt. D、hE CAlls on EACh stuDEnt By nAmE to ContriButE to thE DisCussion.