4、n.Theygrowold.Andtheydie. Astarisbornfromdustandgas.Slowlythedustandgasmakeaball.Theballgetsveryhot.Thenitstartstogiveofflight.Theyoungstargrowsintoagiant.Manyyearsgoby.Theolderstarbeginstogetsmallagain.Atlastitslightgoesout.Thestar'slifeisover.1.Dustand_________makeastar.A.gas B.snow C.