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。
2
Be sure not to lean your head forward or "turtleneck" when pressing shoulder blades together.
记住，当你拉扯肩胛骨时千万不要将头前倾或是做出像乌龟脖子一样的姿势。
3
Famed for public appearances in which he wears his trademark black turtleneck and blue jeans, admirers put Mr Jobs's success down to his dedication to perfection.