姬靖 2021-05-18 00:14 歌词是“这孤城，世界渐冷清”，出自陈奕迅的歌曲《倾城》
I\'m pretty new to Stata. I have a set of observation开发者_运维技巧s of the form \"CountryGDPYear\". I want to create a new variable GDP1960, which gives the GDP in 1960 of each country for each yea
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