?凹足
... hollow back 脊柱前凸 hollow foot 凹足 holoacardius 无心寄生胎畸胎 ...
The finished five-pound foot was a single-piece construction, hollow (to minimize weight) and with no seams or fasteners.
FORBES: Design A New Foot If The Shoe Does Not Fit -- Laser Sintering a Prosthetic Leg
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。