substitution of variable

This paper further inspect through the variable substitution endogenous test and introduce appropriate instrumental variables regression three stage least squares method, to ensure the reliability of the conclusion of the study.

本文通过因变量替换进一步检验和引入合适的工具变量进行三段最小二乘法回归的内生性检验，保证了研究结论的可靠性。

Because we are doing only textual substitution, C is not smart enough to rename our temporary variable if it conflicts with one of the arguments passed to it.

由于只进行文本替换，因此如果这与传递给它的参数冲突，C语言就无法智能地对临时变量重新进行命名。

The substitution of variable crown elevation tailrace tunnel for surge chamber not only can guarantee the safe operation of the powerplant and reduce the investment but also can avoid unfavorable influence of intensively distributed large span underground chambers on the stability of the surrounding rock mass.

用变顶高尾水洞取代调压室，既可保证电站的安全运行和减小工程投资，又避免了大跨度洞室群分布密集给围岩稳定带来的不利影响。

By means of variable substitution and iterative method, this paper puts forth some new higher-order differential equations, and gives their formula of reduction of integrals to common denominator.

借助变量代换、迭代等方法，提出几类新的高阶常微分方程，给出其相应的通积分公式。