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勉強， べんきょう
1. study
2. diligence, working hard
3. experience, lesson (for the future)
4. discount, price reduction
学习
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努力， どりょく
1. effort, exertion, endeavour, endeavor, hard work, striving
努力
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欠く， 闕く， かく
1. to chip, to nick, to break, to crack
2. to lack
会失去物体的一部分或全部；缺乏、应有的东西不足。
に
1. at (place, time), in, on, during
2. to (direction, state), toward, into
3. for (purpose)
4. because of (reason), for, with
5. by, from
6. as (i.e. in the role of)
7. per, in, for, a (e.g. "once a month")
8. and, in addition to
9. if, although
tbd