The author had qualified as a doctor but later gave up the _____ of medicine for full-time writing.

A．prescription

B．procedure

C．treatment

D．practice

患者男性，45岁，用力排便时起病，剧烈头痛，呕吐。短暂意识不清，就诊时颈部强直，右侧下肢疼痛。

首选的检查是（）

A.磁共振

B.头CT平扫

C.X线检查

D.眼底检查

E.腰穿脑脊液检查