Legal analysis: 1. The owner of the exclusive right to a registered trademark cannot prove that the registered trademark was actually used within three years before suing for infringement.

2. If a trademark infringer sells goods that are not known to infringe the exclusive rights of a registered trademark, he can prove that he obtained the goods legally and explain the supplier.

Legal basis: "The People's Republic of China and the Civil Code"

Article 120: If civil rights and interests are infringed upon, the infringed party has the right to request the infringer to bear infringement liability. .

Article 183: If one is harmed due to protecting the civil rights and interests of others, the infringer shall bear civil liability, and the beneficiary may provide appropriate compensation. If there is no infringer, the infringer has escaped or is unable to bear civil liability, and the victim requests compensation, the beneficiary shall provide appropriate compensation.

Article 1,167 If an infringement endangers the personal or property safety of others, the infringed party has the right to request the infringer to bear tort liability such as ceasing the infringement, removing obstacles, and eliminating danger.

Article 1,168 If two or more persons jointly commit infringement and cause damage to others, they shall bear joint and several liability.