—What's this?
— [ ]
A. This is a pen.
B. That's a pen.
C. It's a pen.
D. It's pen.
答案:C
有关原发性脊髓栓系综合征,错误的是()
A.MRI检查有助于诊断
B.终丝直径应大于2mm
C.脊髓信号:T1WI呈低信号,T2WI中高信号
D.椎体形态无变化
E.蛛网膜下腔可扩大
动力黏度μ的物理意义