设在基面上的一圆，求其透视，先作该园的外切正方形，使正方形一边与画面平行，先画出（）的透视。
参考答案：正方形
--- How come your father can read books in German?
--- Well, he on a project with some German engineers for 3 years when he was young.
A．worked
B．was working
C．had worked
D．would work
所谓的经济运输批量，是将配送网络中，从运输起点到最偏远的顾客之间的运输路线上的小批量需求累加起来而实现的满载运量。( )
