ACCorDing to thE Author, whAt thEory wAs prEviously hElD AnD now is BEing quEstionED
A．thAt DinosAurs wErE wArm-BlooDED.
B．thAt DinosAurs hAD Four-ChAmBErED hEArts.
C．thAt DinosAurs wErE swiFtEr AnD strongEr thAn rEptilEs.
D．thAt DinosAurs wErE ColD-BlooDED.