Adjective:

1. not admitting of penetration or passage into or through;

   "an impenetrable fortress"
   "impenetrable rain forests"
   

2. permitting little if any light to pass through because of denseness of matter;

   "dense smoke"
   "heavy fog"
   "impenetrable gloom"
   

3. impossible to understand;

   "impenetrable jargon"
   

1.不能穿过的;刺不进的;透不过的
If you describe something such as a barrier or a forest asimpenetrable, you mean that it is impossible or very difficult to get through.

e.g. ...the Caucasus range, an almostimpenetrable barrier between Europe and Asia.
高加索山脉,几乎难以穿越的欧亚屏障

2.费解的;难以理解的
If you describe something such as a book or a theory asimpenetrable, you are emphasizing that it is impossible or very difficult to understand.

e.g. His books are notoriouslyimpenetrable.
他的书出了名的晦涩难懂。
e.g. ...theseimpenetrable poems.
这些隐晦难懂的诗

impenetrably
...impenetrably detailed reports on product sales.
详细得令人费解的产品销售报告

1. 费解的：impenetrability 不能贯穿 |impenetrable 费解的 | impenetrably 无法通过地

2. 不可穿过的,难以理解的：impervious不能渗透的 |impenetrable不可穿过的,难以理解的. | implore恳求

3. 不透的：impenetability 不渗透性 |impenetrable 不透的 | imperative 强制性的

4. 不能穿透的,不可理解的：inexorable 不为所动的,坚决不变的 |impenetrable 不能穿透的,不可理解的 | incurable 不可救药的

• Coats of mail gilded and silvered and impenetrable.

  出自：Tolkien

• impenetrable banks of rhododendrons bordered the avenue.

  出自：J. Johnston

Their jargon is impenetrable to an outsider.

他们的行话外人听不懂。

I find his style somewhat impenetrable.

我发现他的行为方式令人颇为费解.

The language of this document would be impenetrable to anyone except a specialist.

除了专家,其他任何人都看不懂这份文件.

His books are notoriously impenetrable.

他的书出了名的晦涩难懂。

Still, I had also judged the jungle of both banks quite impenetrable.

其次, 我先前早已留神了,两岸的丛林异常茂密,一眼看不透.

The words died under the impenetrable insolence of Bertha's smile.

在白莎傲慢的,诡秘的笑容面前这几句话被吞下去了.

She raised between them a barrier impenetrable as a wall.

她就在他们之间垒起一道不能越过的界线,象一堵墙一般.

It was a new experience for me to confront an impenetrable wall.

对我来说,面对一堵穿不过的厚墙是一种从未有过的经历.

She was the picture of a serene and exquisite but impenetrable sphinx.

她看上去就象一尊非常安详精致、但又高深莫测的狮身人面像.

His dapper self - confidence seemed impenetrable to such hints.

这类的暗示似乎动摇不了他坚定的 自信.

Their feathers were like armor impenetrable to steel.

它们的羽毛就象刀剑穿不透的盔甲.

He is impenetrable to reason.

跟他道理说不通.

She was imperturbable, inscrutable, impenetrable.

她是不可动摇的, 不可理解的, 不可捉摸的.

The motive for the crime was impenetrable.

那起罪行的作案动机叫人捉摸不透.

Moreover, matter is also impenetrable.

而且, 物质也是不可入的.