Upwards of a billion stars in our galaxy have burnt up their internal energy sources, and so can no longer produce the heat a star needs to oppose the inward force of gravity.

在我们的星系中，超过10亿颗恒星已经耗尽了它们的内部能量来源，因此无法再产生恒星所需的热量来对抗向内的引力。

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Energy Star has a 20-year history educating the public about energy conservation and efficiency.

“能源之星”过去20年来向公众介绍了有关节约能源和能源效益的知识。

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When you do your shopping, look for the Energy Star label.

购买电视时，看看有无能源之星标志。

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The 12, 700-square-foot Energy Star-certified house was crafted from low-toxic materials, withstood air tightness tests on the insulation, and has a water furnace geothermal system that provides hot water, radiant floor heat and air conditioning.

FORBES: Off-The-Grid Mansions

Energy Star exemptions: Federal agencies are required to lease space in U.S. Environmental Protection Agency ENERGY STAR-labeled buildings.

FORBES: GSA Goes Deep Green With Next-Gen Green Leasing Standards

But because buildings must have had 50% occupancy in the most recent year to achieve the ENERGY STAR label, some energy-efficient buildings were ineligible for government leases due to low occupancy.

FORBES: GSA Goes Deep Green With Next-Gen Green Leasing Standards