什么是热制度？
参考答案：
热制度是指在工艺操作制度上控制高炉内热状态的方法的总称。
In our class, when the bell rang and the teacher closed his book, it was a ____ for everyone to
stand up. [ ]
A. signal
B. chance
C. mark
D. measure
城乡环境综合治理“五个方面建设”是指什么？
