Although sCiEntists hAvE long ------- thE humAn AppEnDix As ------- orgAn, thErE is A growing BoDy oF EviDEnCE inDiCAting thAt thE AppEnDix DoEs in FACt hAvE A signiFiCAnt FunCtion As A pArt oF thE BoDy's immunE systEm.
A．ovErEstimAtED ... A minor
B．DisCountED ... A vEstigiAl
C．vAluED ... A mAjor
D．ignorED ... A pivotAl
E．(E) stuDiED ... An inACCEssiBlE