什么是primary data和secondary data?

什么是primary data和secondary data? primitive 和primary区别 initial和primary区别 primary primary primary primary Qualitative和Quantitative Data prime和primary的区别 DATA Data data data 什么是primary demand he secondary demand?primary demand expansion effect of promotion如何解释? Primary和basic和elementary的区别 Experimental primary school 的音标和发音. primary supporting sentences是什么意思?-_-|||什么是初级支持句？ $.each(data,function(index,bankinfo) 和$.each(data.data,function(index,bankinfo)的差别?