单项选择题
A.55% B.65% C.75% D.85% E.95%
A.48h B.24h C.12h D.6h E.2h
A.颈内动脉 B.大脑中动脉 C.大脑前动脉 D.大脑后动脉 E.椎-基底动脉主干