when(it)comestosavingenergy,abigchangesstwhenitcomestosavingenergy,abigchangesstartwithsmallsteps,liketurningoffthelights.为什么括号里用it不用that或别的?

Question

when (it) comes to saving energy,a big changes st
when it comes to saving energy,a big changes start with small steps,like turning off the lights.为什么括号里用it不用that或别的?

Answer 1

when it comes to xxxxx 这是个句型,平时可以记住也这样用；它是用it来指代任何xxx
表示意思为 当谈到xxx,说到xxx
请楼主斟酌,