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困難， こんなん
1. difficulty, hardship, trouble, distress
2. infeasibility, inability (to carry out)
困难；不可行性，无能为力（执行）
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問題， もんだい
1. question (e.g. on a test), problem
2. problem (e.g. societal, political), question, issue, subject (e.g. of research), case, matter
3. question (i.e. doubt)
4. public discussion, controversy
5. trouble, problem, inconvenience, difficulty
问题（例如在考试中），难题；麻烦、问题、不便、困难；问题（如社会性、政治性问题）、疑问、议题、课题（如研究课题）、案例、事项；疑问；公开讨论，争议
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を
1. indicates direct object of action
2. indicates subject of causative expression
3. indicates an area traversed
4. indicates time (period) over which action takes place
5. indicates point of departure or separation of action
6. indicates object of d...
表示动作的直接对象；表示经过的场所；表示离开或分开的点