?显影

... darkroom暗室 to develop显影 developer显影剂 ...

?发达

... 发达 = flourishing 发达 = to develop 发达国 = developing country ...

?开发

开发 exploit; to exploit (a resource); to open up (for development); to develop 开发工具包 development kit 开发工具环境 Development Tools Environment ..

?研制

... 研习 research and study 研制 to develop; to manufacture 研制过程 manufacturing environment ...