impossible to see through or go through不能看透的;不能穿过的
Outside, the fog was thick and impenetrable.外面的雾很浓,什么也看不见。
an impenetrable barrier无法跨越的障碍
impossible to understand费解的,无法理解的
Some of the lyrics on their latest album are completely impenetrable.他们最新专辑中的一些歌词让人完全看不懂。