目前应用最广泛的一种铸造铝合金是铝硅合金。（）
参考答案：对
There was a big fire in the street last night, but the firemen _______ within twenty minutes.
A．took it out
B．brought it out
C．worked it out
D．put it out
水压试验时如何防止锅炉超压？
