利福平属
A．抗疟药B．抗肠虫病药C．抗结核病药D．止血药E．抗贫血药
参考答案：C
提升装置缠绕2层或者2层以上钢丝绳的卷筒，卷筒边缘高出最外层钢丝绳高度，至少为钢丝绳直径的1.5倍。
If marginal cost is above the average cost, when you produce your next unit:（）
A. average cost will decline.
B. marginal cost will remain unchanged.
C. average cost will increase.
