为什么是in the past three years而不是over the past three years

为什么是in the past three years而不是over the past three years in the past few years there have been great changes in my city,为什么是have we _______ on our profect day and night in the past two weeks. 为什么是have worked in the past造句 Memory in the past in the past two in the past翻译 ：in the past century in the past long in the past few Trapped in the past in the past 一道语法题 in the past decade,geologists have come clo一道语法题in the past decade,geologists have come closer than ever to ( )the age of the earth为什么是 calculating不是calculate 题目为The life in the past的英语作文 “In the past,my hometown was very small”为开头 Great changes have taken place in Shanghai in the past 5 years.为什么是have taken place而不是have been taken place 不需要被动吗? Great changes ---- in my hometown in the past few years.A.took place B.have taken placeC.have been taken place D.were taken place为什么是B? __is known to us all is that the old scientist,for___life was hard in the past,still works veryhard in his eighties.为什么是what whom第一个为什么不能用as 第二个为什么是whom