同调函子

The first 10 chapters study cohomolgy of open set in Euclidean space,treat smooth manifolds and their cohomology and end with integration on manifolds.

全书分四章：范畴与函子及其在模论中的应用；特殊模与相应的维数；环模复形的同调理论；谱序列。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。