北方长龙：公司具有无人机类相关业务及产品，该类业务收入占公司营业总收入比例极小

Group 1 - The company, Beifang Changlong (301357.SZ), has indicated that it has business and products related to drones, which are applicable in the aerospace field [2] - The revenue from the drone-related business constitutes a very small proportion of the company's total operating revenue, contributing minimally to overall income [2] - The company advises investors to be cautious of trading risks in the secondary market and to make rational investment decisions to avoid losses due to speculative trading [2]