the exterior protective or supporting structure or shell of many animals (especially invertebrates) including bony or horny parts such as nails or scales or hoofs
exoskeleton详细解释
ex.o.skel.e.ton n.（名词）A hard outer structure, such as the shell of an insect or a crustacean, that provides protection or support for an organism.外骨骼：为生物提供保护或支持的坚硬的外部结构，象甲壳类动物或昆虫的骨盘 【引伸】 ex.oskel.etal
