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self-study; teaching oneself
studying by oneself (at school) while the teacher is absent
放課後の自修時間に苦手科目を復習した。
I reviewed my weak subjects during self-study time after school.
図書館で毎日二時間の自修を続けている。
I continue studying on my own for two hours every day at the library.
毎日自修することが上達の近道だ。
Self-study every day is the quickest path to improvement.