Rule reminder
'Abbastanza/sufficientemente + adjective/adverb + da + infinitive' = enough to (same subject). 'Troppo + adjective/adverb + per + infinitive' = too ... to (same subject). Both use the infinitive because the subject of both clauses is identical.
Il candidato era abbastanza esperto _____ ricoprire l'incarico senza supervisione.