In the past three years ,he ____the country twice.

In the past three years ,he ____the country twice. In the past three years You___a lot in the past three years. 为什么是in the past three years而不是over the past three years In the past three years ,he ____ very hard at maths. A.works they --all over the country in the past ten years In the past three years there great changes in Beijing. Great changes _____ in Hainan in the past three years. in the last three years和in the past three years的区别 in the past three past Nanjing__(change)a lot in the past three years. in the past three years是用过去完成时还是现在完成时?