It was extremely dark.

非常黑暗。

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In this photo below, the water is extremely dark, and gives the feeling of being out in deep water ocean.

下面这张图上水的颜色非常深，看起来像在深海之上出游。

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At night this glow is known as the gegenschein (German for "counter glow"), and can be seen as a faint glow in an extremely dark sky.

这种夜空中的辉光，就是所谓的对日照(德文的意思即为“对面的辉光”)，只有在非常非常暗的夜空中，才能看到这种很暗的辉光。

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John Lloyd-Jones, representing Hinton, said his client had "extremely dark and disturbing fantasies".

BBC: John Hinton