众所周知,零这一特殊数字在数学中具有特殊作用。例如,零是正整数和负整数的界线;在数轴上零叫作起点;零乘任何不是零的数都是零;……类似零这一特殊数字在数学中所起的作用,我们还可以找出许许多多,我不是学数学的,更不敢在众多数学教师面前卖弄,我只是把零这一数字在地理学科 As we all know, this special number of zero has a special role in mathematics. For example, zero is the boundary between a positive integer and a negative integer; zero is called a starting point on the axis; zero-multiplication is a zero if any number is not zero; ... we can also find the role of the zero-like special number in mathematics. There are so many, I am not studying mathematics, and I dare not show off in front of many math teachers. I just put zero in this figure in the discipline of geography.