嘴唇颜色比较暗，发黑的原因？

Labial color is darker, nigrescent reason?

youdao

所以，正门总是比较暗。

Therefore, the main entrance was dark.

youdao

天花板是蓝色的，所以屋子的光线才比较暗。

The ceiling is blue maybe that's why the room looks dark.

youdao

If your have good eyesight from the distance that you're at you can see the vessels leading out of the heart and into the lungs, and the lungs are these darker spaces within the ribcage.

如果你的视力足够好的话,你们能看到,由心脏发出血管,进入到肺部,肺是胸腔里这片比较暗的部分

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