Technology diffusion is the application and promotion of innovative technologies in other economic fields and a larger geographical space. From a geographic perspective, technology diffusion is the spatial flow and transfer of technology. According to the above definitions, which of the following is technology diffusions? ['Multiple pharmaceutical factories in a province use the same long-recognized formula to produce a drug.', 'City A has developed its own characteristic industry by drawing on the innovative industry technology of City B.', "A company's production creative cup is applied by a foreign artist to his artistic creation.", "Employees of a company's R & D department leak core R & D secrets to the company's competitors."]