近30年来，国外森林采伐技术发生了巨大的变化，已经开始实现全盘机械化。

There has deen a great change in forest harvesting technology in theworld during last 30 years.

youdao

近30年来，国外森林采伐技术发生了巨大的变化，已经开始实现全盘机械化。

There has deen a great change in forest harvesting technology in theworld during last 30 years.

youdao