简述连铸对钢水的基本要求。
参考答案:
连铸对钢水的基本要求是:(1)钢水质量:稳定和一定的浇注温度、纯净度、成分和可浇性;(2)钢水供应节奏:稳定和一定的钢水量和供应时间
—Do you know the boy under the tree?
—Yes, I know. He is creative and imaginative, but he is a little lazy _______. [ ]
A. once a time
B. at a time
C. at times
D. at time
施工成本计划的编制依据有哪些?