Core Viewpoint - The article emphasizes the importance of adjusting to the new WeChat mechanism for better access to content and updates from the platform [1]. Group 1 - The course offered is a premium product with no exams or certificates, and a training certificate can be applied for after completing the course within the validity period [5]. - The course is a virtual product and is non-refundable after purchase, with the option to apply for a VAT electronic invoice during the purchase [6]. - The validity period of the course is 360 days from the date of purchase, allowing unlimited access to learning materials during this time [6].

Group 1 - The article promotes a free book giveaway, specifically the "Liquid Chromatography Practical Handbook" published by Instrument Information Network [2] - It highlights the importance of setting the account as a star to ensure users receive future updates [1] Group 2 - The course offered is a premium course without exams or certificates, and it allows for unlimited learning within a specified validity period [6] - The course is a virtual product and is non-refundable after purchase [6] - Users can apply for a VAT electronic invoice upon purchase [6]