8) Most of the world's automobiles run on energy acquired from petroleum. Like all fossil fuels, petroleum is a nonrenewable energy resource. This means that it is a resource that cannot be replaced as quickly as humans use up existing supplies. Humans face a problem because once petroleum reserves begin to run out, there won't be enough fuel to power all the automobiles in the world. Which of the following is the best potential long-term solution to this specific problem of energy supply?
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Use more petroleum, but make sure it is used only in fuel-efficient automobiles.
Maintain current consumption of petroleum, but use it only to manufacture plastics.
Use a cleaner fossil fuel, such as natural gas, to power automobiles.
Use renewable resources, such as solar energy, to power automobiles.
Use renewable resources, such as solar energy, to power automobiles.
9) Which of the following could be considered a responsible way to manage a natural resource?
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replanting forests that have been cut down for lumber use
driving a gas-powered car everywhere
growing the same crop every year on a plot of farm land
dumping used chemicals into an isolated lake