1. The exclusive right to use a trademark shall be ten years from the date of registration announcement. 2. The renewal can be carried out before the expiration of trademark registration1February and 6 months after the expiration. 3. The nature of enterprise B belongs to trademark infringement. Without the permission of the registrant, unauthorized use of similar registered trademarks of others belongs to trademark infringement. 4. Kaoliang liquor is a common name of liquor, which has no obvious characteristics and cannot be registered as a trademark. 5.c is the first user. In general, C can be used within the original scope.