小题1: Which road sign tells us that we must NOT turn right?

小题2:Outside our school there’s a sign like this. What should the drivers to when they see it?

A．They must stop the car immediately and wait there.

B．They must take a U-turn there.

C．They mustn’t even stop the car in that area.

D．They mustn’t drive the car into that area.

男性，40岁。因两上肢无力伴肌萎缩，肉跳1年就诊。无感觉障碍、尿失禁。体检：两侧肩部肌力5级，肘关节肌力5级，腕关节肌力4级，对掌肌及骨间肌力2～3级，双上肢肌张力略增高，双侧肱二头肌、肱三头肌反射（+++），右侧霍夫曼征阳性；左侧巴氏征阳性；双侧大小鱼际肌、骨间肌均有不同程度萎缩。

本患者除临床诊断外，还须首选哪项检查以便和脊髓空洞症相鉴别诊断（）

A.脊柱CT扫描

B.诱发电位检测

C.腰穿

D.椎管造影

E.颈髓磁共振成像