It is formed by the action of wind and water on rocks over thousands of years.

VOA: special.2009.09.14

So your tastes in music evolve over thousands of years.

你对音乐的品味随时间发生变化。

耶鲁公开课 - 死亡课程节选

He says looking back thousands of years can help researchers look forward by understanding how a disease changed over time.

VOA: special.2010.06.29

Much of the information came from observations made by thousands of volunteers in more than four thousand places over forty years.

VOA: special.2009.05.12

The thirty-five thousand works of art in the museum represent thousands of years of human culture and come from all over the world.

VOA: special.2010.06.23

"Because it's happening so quickly, they haven't had time to adapt and change, if you imagine a climate changing over hundreds of thousands of years, bears and other animals would gradually move into other habitats,but because this is going to happen over decades, it will be too fast for them to adapt and look for other food sources,"

VOA: standard.2009.12.13