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同士， どうし， どし
1. fellow, mutual, companion, comrade
同伴，伙伴，伴侣，同志
と
1. if, when
2. and
3. with
4. used for quoting (thoughts, speech, etc.)
5. promoted pawn
6. indicates a question
表示引用
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
