环指

The homologs of benzene are those containing an alkyl group or alkyl groups in place of one or more hydrogen atoms.

苯的同系物是指是那些苯环上有一个或多个氢原子被一个或多个烷基替代而构成的物质。

2 Petroleum crude oil: Refers to naturally occurring crude oil that is mixtures of hydrocarbon compounds that contain mainly paraffin hydrocarbon, cycloparafin hydrocarbon, and aromatic hydrocarbon.

二石油原油：指一种源于自然界之原油，为碳氢化合物之混合物，其主要成分为石蜡烃、环烷烃、芳香烃等。

2 Petroleum crude oil: Refers to naturally occurring crude oil that is mixtures of hydrocarbon compounds that contain mainly paraffin hydrocarbon, cycloparafin hydrocarbon, and aromatic hydrocarbon.

二石油原油：指一种源于自然界之原油，为碳氢化合物之混合物，其主要成分为石蜡烃、环烷烃、芳香烃等。你知道它的英文吗？

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。