The difference of PC and NC in different economic level group had statistical significance(P<0.001).
不同经济水平组NC、PC的差异都有统计学意义（P<0.001）。
Different groups'current economic level will give different endogenous effect to different pollutant.
②不同组别的当前经济水平会给不同污染物带来不同的内生性影响。
Different groups' current economic level will give different endogenous effect to different pollutant.
不同组别的当前经济水平会给不同污染物带来不同的内生性影响。
It has been proved that people of different-level education play different voles in economic activities.
实践证明，接受不同层次和水平教育的人在国民经济活动中，会产生不同的经济效益。
It has been proved that people of different-level education play different voles in economic activities.
实践证明，接受不同层次和水平教育的人在国民经济活动中，会产生不同的经济效益。
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