实例变量

例句：

1. 1. This is an instance of a rare species.
   这是稀有物种的一个实例。
2. 2.The teacher used the example of the Great Wall to explain the concept.
   老师用长城的例子来解释这个概念。
3. 3. The scientist illustrated his theory with several instances.
   科学家用几个实例来说明他的理论。