Explanations:
उपरोक्त वाक्य के रेखांकित भाग had been addicted to gamble for के स्थान पर had been addicted to gambling का प्रयोग होगा क्योंकि preposition 'to' के बाद verb का ing form use होता है। Note – Addict to something Addict to doing something Correct sentence – He had been addicted to gambling for past 5 years