H2S探测器采用的传感器测量原理为（）。
A.热敏传送
B.电化学
C.密度
参考答案：B
______ he explained it to me did I make sense of what he said.
A．Hardly had
B．Not until
C．Shortly after
D．No sooner
常以突发截瘫为首发症状的是（）
A.颈内动脉海绵窦瘘
B.脑蛛网膜下隙出血
C.脑动静脉畸形
D.脊髓血管畸形
E.颈内动脉-后交通动脉动脉瘤
