地租是一种经济剩余,即( )之后余下的那部分。
A.总利润减去税金 B.总收入减去总要素成本C.税后总利润减去社会平均利润 D.总收益减去生产成本
参考答案:B
What does the passage mainly discuss a. Trends in teaching mathematics to children. b. The use of mathematics in child psychology. c. The development of mathematical ability in children. d. The fundamental concepts of mathematics that children must learn.
最小二乘法确定直线回归方程的基本原则是使各观察点
A.距直线的纵向距离相等B.距直线的纵向距离的平方和最小C.与直线的垂直距离相等D.与直线的垂直距离的平方和最小E.与直线的垂直距离和的平方最小