液化气失火后，灭火人员应站在上风处灭火，要向液化气钢瓶大量浇水使其冷却，以防爆炸。
参考答案：对
— Did you call on any of your old friends when you returned to your hometown ?
—______ of them . They were all very busy .
A．Nobody
B．None
C．Both
D．Neither
制备蜡丸所用的辅料为（）
A.石蜡
B.川白蜡
C.蜂蜡
D.液状石蜡
E.虫蜡
