81.由矢狀面(sagittal plane)觀察,下何者屬前凸(lordosis)曲度?(A)頸椎(cervical vertebrae)、散椎(sacral vertebrae(B)頸椎(cervicalvertebrae、腰椎(umbar vertebrae)(C)頸椎(cervical vertebrae)、胸椎(thoracic vertebrae)(D)胸框(thoracic vertebre)、骶椎(sacralvertebrae)