Lighting accounts for about 7% of the total electricity consumed in the US. Since lighting is often far removed from the power source—such as the distance from a power plant to street lamps on a remote highway—a lot of energy is lost during transmission.

在美国，照明约占总耗电量的7%。由于照明通常远离电源——例如从发电厂到偏远公路上的路灯——因此大量的能源在传输过程中会损失掉。

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When a wave travels uniformly in all directions from a small source, the intensity varies inversely as the square of the distance.

当波从小扰动源向各个方向均匀传播时，其强度的变化与距离的平方成反比。

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The strength of RF fields is greatest at its source, and diminishes quickly with distance.

射频场的力量在射频源最强，并随距离而迅速减弱。

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Certainly, distance from the source and dilution in the atmosphere lowers exposure risk.

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Tyrrell says that unlike with widely dispersed asbestos, the pattern in most toxic-tort cases is to settle with everyone living some critical distance from the source.

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In the specific case of maize, to ensure that seed stocks achieve 99.9% purity, a separation distance of 200 metres is required from any source of "contaminating" maize pollen.

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