朗迪集团：主营业务为家用空调风叶、机械风机、复合材料等，未发生重大变化

Group 1 - The company, Langdi Group (603726), has announced unusual fluctuations in its stock trading [1] - The main business of the company includes household air conditioning blades, mechanical fans, and composite materials [1] - An internal review by the company revealed that there have been no significant changes in its product structure or main business [1] Group 2 - The company's production and operational activities are currently normal [1] - There have been no significant changes in the internal and external operating environment or industry policies [1]