高速钢可用于冲击较大的场合，也可用于高速切削。
参考答案：错
12. They were astonished _____ the news of his escape from prison.
A．for
B．in
C．at
D．to
狮子山楚王陵主墓室封堵墓门的塞门石有几块？每块重量约几吨？
