it continues to pile up deeper and deeper year after year and century after century是什么意思?

it continues to pile up deeper and deeper year after year and century after century是什么意思?
it continues to pile up deeper and deeper year after year and century after century是什么意思?

it continues to pile up deeper and deeper year after year and century after century是什么意思?
一年又一年,一个世纪又一个世纪,它持续地堆积起来,越堆越深.