The particular design of muscles and bones in the neck and limbs of the turtle allow that it can draw in its exposed parts such that an attacker can find nothing but hard shell to bite.

海龟颈部和四肢的肌肉及骨骼的特殊设计使它能把暴露在外的部分缩回去，这样攻击者只能去咬坚硬的外壳。

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Some of these coats are hard—like the shell of a nut—for extra protection.

其中一些表皮很坚硬——就像坚果的外壳——可以提供额外的保护。

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Why doesn't he carry a hard and heavy shell?

他为什么不带一个又硬又重的壳呢？

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The laser, which made a rapid-fire popping sound, cut cleanly and quickly through the outer shell of a hard-boiled egg.

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It offers the full protection of a hard-shell case with an ultra-thin, light-weight, low-profile design.

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P3 folds up for easy storage, and stows away into its own compact hard-shell carry case.

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