to achieve a high level of mastery or profound attainment in scholarship, art, or a particular skill; to have reached an advanced stage of proficiency.
经过多年的刻苦钻研，他在这个领域已经入室升堂，成为了一位受人尊敬的专家。
After years of diligent study, he has achieved mastery in this field, becoming a respected expert.
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