That might not seem surprising in this age of electric lights and round-the-clock activities, but co-author David Samson says this shift began long before we developed artificial lighting.

在这个有电灯和通宵工作的时代这也许并不令人惊讶。 但是这份报告的共同作者大卫•萨姆森说，睡眠的这种变化早在我们发明人工照明之前就开始了。

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The company said its new round-the clock service was to "support shift workers and the night-time economy".

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With its overall sales rising, Chrysler is adding a third shift at Belvidere, putting the plant on round-the-clock production.

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