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来源:雅诚德英语网
Generating enough light could be prohibitively expensive, unless cheap, renewable energy is available, and this appears to be rather a future aspiration than a likelihood for the near future.
除非有廉价可再生能源,否则制造足够光的成本可能会高得令人望而却步,而这似乎只是未来的愿望而非近期能实现的。