The school survey showed that the students' attitudes to how to deal with difficulties in life      widely. [ ]

A. fell

B. varied

C. expanded

D. spread

男，25岁，平素体健，因膝关节外伤在腰麻下行膑骨切除术。术后第2天发生剧烈头痛，坐起时加重，平卧后减轻，该病人术后头痛发生的原因是（）

A.局麻药中加入肾上腺素

B.腰麻后脑脊液外流引起的低压性头痛

C.同时伴有颅内病变

D.麻醉药物选择不当

E.腰麻穿刺针太粗