说明：  常用的数值积分方法(特别是梯形、Simpson方法、和Romberg算法)，编制复合梯形公式，复合Simpson公式，Romberg算法的程序，数值积分方法的逐步精致化过程
(Commonly used numerical integration methods (in particular, trapezoidal, Simpson method, and the Romberg algorithm), the preparation of composite trapezoidal rule, composite Simpson formula, Romberg algorithm procedure, numerical integration process of gradual refinement)