锅炉超压时，应采取（）措施和降压操作，待严重超压消除后，再做进一步处理。
参考答案：降压
已知一个多边形的内角和与外角和的比是2∶1，则它的边数为（ ）
A．9
B．8
C．7
D．6
In the good care of the nurses, the boy is ___ recovering from his heart operation. [ ]
A. quietly
B. actually
C. practically
D. gradually
