▲这类用法中的介词通常不能省略。补充一句，除你提到的介词外，还有一个经常用于这类结构的介词 over。如：

He has been on dialysis for the past three years. 近三年来他一直在做透析。

She has won the race in the last five years. 过去5 年里，她一直是此项比赛的冠军。

Our region has made great advances over the past ten years. 在过去十年中，我们地区有了很大发展。

People have changed their diets a lot over the past few years. 过去几年里人们的饮食习惯改变了许多。

There’s been a progressive decline in the standard of living over the past few years. 最近几年的生活水准每况愈下。

Ben’s case is not unique but one of several I have come up against during the past few years. 本的案子并不特殊，我在过去的几年中也碰到了几起这样的案子。

▲不过，有一类与之相似的结构 these past / last few years 则是通常不用介词的。如：

The housing market has been very sluggish these past few years. 过去这几年房地产市场一直很萧条。

Sniper fire has claimed countless lives these past few weeks. 这几个星期以来，无数人在狙击手的枪口下丧命。

The North of England has been experiencing Arctic conditions these past few days. 过去的几天里，英格兰北部地方天气极其寒冷。

I’ve been so busy these last few days, what with one thing and another. 我最近几天忙这忙那地忙个不停。

The family has had a tough time of it these last few months. 最近几个月这家人日子很难熬。