The mainstream of energy sources are non-renewable fossil fuels and the growing scarcity will.

主流能源的化石燃料是不可再生的，稀缺性会日益增强。

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Although they are manufactured using non-renewable fossil fuels, they last much longer than plastic shopping bags and can be reused many times over.

虽然它们是用不可再生的化石燃料制作而成的塑料袋，但是比普通的塑料购物袋经久耐用多了，反复使用很多次它都不容易坏。

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Problems associated with this reliance on petroleum include fluctuating petroleum costs, uncertainty of supply and ultimately concerns relating to the depletion of these non-renewable fossil fuels.

和依赖石油相关的问题包括石油成本的波动，供应不稳定，并且最终的问题是这些不可再生的旧资源的枯竭。

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China will "endeavor" to cut emissions of carbon dioxide -- the most prevalent of the greenhouse gases that cause climate change -- by "a notable margin" in coming years, Hu said, adding that China also will "vigorously develop renewable energy and nuclear energy" with the goal of increasing the share of non-fossil fuels in total energy consumption to 15 percent by 2020.

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