Rule reminder
Review of all B2 vocabulary topics: in-/im-/il-/ir-, ri-, dis- prefixes; -zione/-mento/-ezza/-ità/-oso/-abile/-ibile/-evole suffixes; diminutives (-ino/-etto/-ello), augmentatives (-one), pejoratives (-accio/-astro); word families; compound words; register (usare/utilizzare/impiegare); false friends and near-synonyms.
Which word correctly completes: 'Il suo comportamento era del tutto ___.' (His behaviour was completely irresponsible.)