紧急停车时，如何降低转化炉温度？
参考答案：
降低转化炉燃料气流量；关闭部分火嘴；控好汽包液位和压力。
It's believed that movies, also_______ motion pictures, arrived in China near the end of the 19th century. [ ]
A. to be called
B. to call
C. calling
D. called
内容重要并紧急需要打破常规优先传递处理的文件叫做( )。
A．平件 B．加急件 C．特急件 D．急件
