车外警戒时，押运员应打开（）和枪机（），双手持枪跨立或在小范围内游动警戒，及时制止无关人员靠近，随时做好处置突发事件的准备
参考答案：枪托；保险
_______,but he still could not understand it.
A．He had been told many times
B．Having been told many times
C．Told many times
D．Although he had been told many times
下列不属于国家颁布的淘汰目录的灭火器的是（）。
A.酸碱型灭火器
B.化学泡沫型灭火器
C.倒置使用型灭火器
D.卤代烷灭火器
