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持ちつ持たれつ， もちつもたれつ
1. helping each other, supporting each other, mutual cooperation, give and take, reciprocity, interdependence
互帮互助、相互支持、相互合作、有得有失、互惠互利、相互依存
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
