腰椎牵引时产生摩擦力的重量约为人体体重的（） ["40%","50%","60%","70%","80%"]
是硬膜外截瘫的主要原因（） ["空气栓塞","硬膜外血肿","硬膜外脓肿","全脊髓麻醉","刺破胸膜","脊神经根损伤"]
内毒素的毒性分子是（） ["脂蛋白","核心多糖","类脂A","特异多糖","磷脂"]
与穿破硬膜外血管及注射空气有关（） ["空气栓塞","硬膜外血肿","硬膜外脓肿","全脊髓麻醉","刺破胸膜","脊神经根损伤"]
细菌细胞壁的主要成分是（） ["脂蛋白","磷壁酸","RNA","脂多糖","肽聚糖"]
凝结水除盐后二氧化硅（）10ug/kg。
