essential difference

• 主要区别

essential difference的用法和样例：

例句

1. The only difference is that, the vertex positions are stored only for key-frames.
   其主要区别是，它的顶点位置仅用来存储关键帧。
2. The primary difference among the bicycles in a product model is the color and the size.
   同一产品型号的不同自行车的主要区别在于颜色和尺寸。