GRE Logical Reading: ETS-GRE逻辑单题ETS - NIR0BDR61F5S6NDCK$

Years ago, consumers in Frieland began paying an energy tax in the form of two Frieland pennies for each unit of energy consumed that came from nonrenewable sources. Following the introduction of this energy tax, there was a steady reduction in the total yearly consumption of energy from nonrenewable sources.