during the past 20 years 和 over the past 20 years一样吗?

during the past 20 years 和 over the past 20 years一样吗? over the past ten years It during the past five years in the past few years和over the past few years有什么区别? in the past 3 years 和 over the past 3 years的区别 Over the past ten years ,over这里是介词吗 over the past ten years是什么意思 Over the past fifty years,young 这个 in the past over xxx years说法 ok吗 over the past ten years能加过去完成时吗? During the past two years与in the past two years区别 为什么是in the past three years而不是over the past three years