Once a patent expires， an invention becomes common property and can then be freely used by anyone。（ ）
举一反三
- A patent is an intellectual property right for a technical invention。 It allows you to prevent others from using your invention for commercial purposes forever。（ ）
- There three types of patent in China, Patent for Invention, Patent for Utility Models and Patent for .
- Which tools can be used to search patent? A: Espacenet patent search B: WIPO Patentscope C: CNIPA patent search and analysis D: USPTO patent search
- The credit cards can be used everywhere and by anyone, so current economy can be regarded as credit economy. A: 正确 B: 错误
- The difference between an invention patent and a utility model patent is (). A: Invention must be the proposal and innovation of new methods B: The utility model must be a product with shape and structure C: The creative requirements of utility model patents are lower than invention patents D: Some products cannot declare utility model patents