Rule reminder
B2 MASTERY: At this level you must control all conditional types, formal alternatives (qualora/ove/nel caso in cui/purché), inverted conditionals, mixed conditionals, modal verbs in conditionals, journalistic conditional, and register appropriateness — simultaneously.
A UN diplomat writes: '_____ le trattative non _____ a un accordo entro il termine stabilito, si renderà necessario l'intervento di un mediatore internazionale.'