单项选择题
A.superior gluteal artery. B.sciatic nerve. C.posterior femoral cutaneous nerve. D.pudendal nerve. E.internal pudendal vein and artery.
A.tibial nerve B.common peroneal nerve C.popliteal vein and its tributaries D.popliteal artery and its branches E.deep peroneal nerve
A.anterior longitudinal ligament B.posterior longitudinal ligament C.interspinal ligament D.ligamenta flava E. supraspinal ligament