The skin on her hands was hard and rough.

她手上的皮肤粗糙而没有弹性。

《牛津词典》

The hard shell on a beetle is an outside protection, as is the "skin", called cuticle, of an earthworm.

甲壳虫身上的硬壳是外表保护层，就像蚯蚓的“皮肤”，它叫角质层。

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If you notice a patch of hard, pale, cold skin, you may have frostbite.

如果你在皮肤上发现硬的靑的冷的斑点，那你可能生了冻疮。

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However, in a beat-em-up he has a fundamental problem, which is that his superpowers are either less powerful versions of Superman powers (strength, tough skin) or hard to implement as other than special attacks (fish telepathy).

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The condition causes dots of hard, thickened skin which are painful and uncomfortable.

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The patient also received lower eyelids, upper lip, skin, muscles, bone, hard palate, arteries, veins and nerves.

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