1·Despite the strength of its site, the old fortress at Dover was not impregnable.
尽管占据地利优势，多佛古堡也不是坚不可摧的。
2·Despite Microsoft's impregnable strength as a producer of software, its foray into hardware brings it up against two other considerable powers, both from Japan: Sony and Nintendo.
作为软件巨头，微软坚不可摧。但是，在硬件它上却碰到两位强大对手：日本的索尼和任天堂。
3·Once impregnable, they are now defenceless against the thousands of tourists who swarm here each year to relax on the plethora of beaches and marvel at the imposing fortresses.
这些城堡曾经坚不可摧，如今却对每年来到这里的成千上万的游客敞开了大门。游客们在这里众多的海滩上尽情放松自己，他们对这些宏伟的城堡赞叹不已。
4·Impregnable: a woman whose memory of labor is still vivid.
坚不可摧(字面意思：不能再怀孕的，词根：pregnant)：形容对分娩记忆犹新的女人。
5·But we hit an impregnable wall when it comes to free flow across the world of people eager to maximize the value of their labor.
而当我们作为世界人民，想要最大限度地发挥自己的劳动力价值时，就有一道坚不可摧的墙横在我们面前。