development period短语¹³¹⁶²⁰⁺³ 基本例句 开发期 From the60's of20th century up to now, the development of the world GIS experienced four stages: Expanding period consolidating period, development period and the consumers' period. 从20世纪60年代至今，世界 GIS的发展经历了四个阶段：开拓期、巩固发展期、大发展期和现在的用户时代。 cnki