Ababymightshowfearofanunfamiliaradult,_______heislikelytosmileandreachouttoanotherinfant.
Humanbehaviorismostlyaproductoflearning________thebehaviorofanimalsdependsmainlyoninstinct.
ShegotajobasanassistantstagemanagerattheCambridgeArtsFestivalTheatre,thinkingthatitmight________toacareerasaplaywright(剧作家).