等量线

例句：

1. 1. The distribution of resources is often dictated by the need for equilibrium.
   资源的分配往往需要达到平衡。
2. 2. In economics, the concept of equilibrium is crucial in determining market behavior.
   在经济学中，平衡的概念对于确定市场行为至关重要。
3. 3. The graph shows a line of equal height, indicating that the forces are balanced.
   该图显示了一条等高线，表明力是平衡的。