等产量线上某一点的切线的斜率绝对值等于()。
A、预算线的斜率
B、等成本线的斜率
C、边际技术替代率
D、边际报酬
参考答案:C
I'd like to know if Lin Tao is the second _____ boy in his class. [ ]
A. older
B. the older
C. oldest
D. the oldest
红肌