The authors want to deduce a brief formulation, and use all-purpose program to get exact result for echelon, rectangle and rotundity crosssection.
作者想推导简短的公式，对梯形、矩形和圆形断面采用通用的程序，以得到准确的结果。
2
This law abolished special educational requirements for federal jurors and required them to be selected at random from a crosssection of the entire community.
该法案废除了对联邦陪审员特定的受教育水平的要求，并要求联邦陪审员是随机选自全社会各阶层的。
3
Bidders are shown only a crosssection of the ribs.