dual of tangent space

例句：

1. 1. The dual role of a leader is to inspire and lead.
   领导者的双重角色是激励和领导。
2. 2. The dual challenge of managing time and meeting deadlines can be overwhelming.
   管理时间和满足截止日期的双重挑战可能会让人感到压力巨大。
3. 3. In the dual economy, both sides must work together for success.
   在双重经济中，双方必须共同努力才能取得成功。