再生胶的制造工艺分为废胶分类、切胶、洗胶、粉碎、（）等工段或工序。
参考答案：再生精炼
处理瓦斯、煤尘爆炸事故时，矿山救护队的主要任务是什么？
. He was late for the meeting because the bus he took ______ halfway.
A．broke in
B．broke down
C．broke out
D．broke up
