Exposure is more efficient, energy foot, machine lighter weight.

曝光效率更高，能量足，机器重量更轻。

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Houses built before 1939 use about 50% more energy per square foot than those built after 2000, mainly due to the tiny cracks and gaps that expand over time and let in more outside air.

1939年以前建造的房屋每平方英尺消耗的能源比2000年以后建造的房屋多50%，这主要是由于微小的裂缝随着时间的推移而扩大，更多的外部空气进入了裂缝。

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It's quite possible that someone living in an older, 2, 000-square-foot, two-bedroom house could use more energy than a family living in a new 6, 000-square-foot McMansion.

也就是说，一家住在2000平方英尺带有两个卧室的老式的房子里的人，很有可能比一家住在6000平方英尺全新的庞大房子中的人耗费更多的能源。

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So despite the fact that our homes have become remarkably more energy efficient with a nearly one-third drop in total energy per square foot, residential energy demand didn't go down--it went up about a third over the two-decade period.

FORBES: Magazine Article

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

Its second-generation Ankle Mimicking Prosthetic Foot (AMP-Foot 2.0) uses a pair of force sensors to determine the leg's relative position and let an actuator build energy when the foot bends, locking the power away to use only when the owner pushes off.

ENGADGET: AMP-Foot 2.0 prosthesis gives the power of real feet, keeps a light step (video)