A bi-directional association is indicated by a solid line between the two classes. 一个双向关联用两个类间的实线表示。
The car was full of the soldiers. 车子上满载着士兵。
A bus full of politicians was speeding down a country road when it swerved into a field and crashed into a tree. 一辆满载政客的大汽车正沿着一条乡间道路快速行驶,突然,汽车偏离方向驶入田间,撞上大树。