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すみません， 済みません
1. excuse me, pardon me, I'm sorry, I beg your pardon
2. thank you, you shouldn't have, it's too much
对不起，劳驾，不好意思，请原谅；谢谢！费心了！
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なのだ， なんだ
1. it is assuredly that ..., can say with confidence that ...
2. did not ...
〜んだ句型；可以肯定地说……，可以有把握地说……
が
1. indicates the subject of a sentence
2. indicates possession
3. but, however, (and) yet, though, although, while
4. and
5. used after an introductory remark or explanation
6. regardless of ..., whether ... (or not), no matter ...
7. indicates a des...
tbd