Jefferson骨折是指（）
A.环椎齿状突尖端骨折
B.寰椎前后弓双侧性骨折
C.损伤性枢椎椎弓骨折
D.颈椎体压缩骨折
E.枢椎棘突骨折
参考答案：B
The teacher and writer _____ the lecture. It'll be finished in half an hour. [ ]
A. have gone to
B. have been to
C. has gone to
D. has been to
休克早期血压及脉搏的变化是（）
A.收缩压下降，舒张压下降，脉搏细速
B.收缩压正常，舒张压下降，脉搏细速
C.收缩压正常，舒张压升高，脉搏徐缓
D.收缩压正常，舒张压升高，脉搏细速
E.收缩压增高，舒张压正常，脉搏细速
