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授業， じゅぎょう
1. lesson, class, teaching, instruction, classwork, schoolwork
课、课程、教学、指导、功课、学业
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単位， たんい
1. unit, denomination
2. credit (in school)
3. in units of (e.g. "in thousands"), in amounts of
(计量、计数等)单位；学分（在学校）；以单位计(例如"以千计")
は
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis
指示句子的主题；表示与另一选项（无论是否明确提及）形成对比；表示强调
