燃炉正常工作的标志是什么？
参考答案：
炉子正常运转，各阀灵活准确，温度压力稳定，达到制粉工艺要求。
The English play _____ my classmates acted at the new year's party was really a great success. [ ]
A. for which
B. at which
C. in which
D. on which
对于地基承载力较低、台身较高、跨径较大的梁桥，应优先选用的桥台形式是( )。
A．轻型桥台
B．框架式桥台
C．重力式桥台
D．柱式桥台
