The phosphorus at the bottom of the ocean has to somehow make its way back to the surface, to complete the cycle, to begin the cycle all over again.

海底的磷必须找到某种方式回到表面，以完成这个循环，从而重新开始这个循环。

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An owl's head, for example, can twist so far round that it faces backward, but when the bird wants to look forward again, it must turn its head back the way it came.

比如说猫头鹰可以将正脸一直转到后脑勺的位置，但是如果它再想看到正前方的东西，那整个头部只能原路返回了。

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The jaguar just sometimes went out of its house with its “girlfriend”and stayed in the sun for a while before it came back to its house again.

然而此举并未带来多大改观,那只老虎最多陪伴外来的“女友”走出虎房,到阳光下站一站,不久就又回到它的“卧室”。

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If I then put it back into its original condition, lower the heat say, temperature back to body temperature and reduce the pH down to seven again, the molecules will re-nature.

假如我把烧杯的温度恢复到初始状态,降低温度,温度降低到体温,将pH值降低到七,这些分子会复性

耶鲁公开课 - 生物医学工程探索课程节选

And fortunately, as a result, today, the auto industry is back on its feet again, and more importantly, people are back at work collecting a paycheck, taking care of their families.

WHITEHOUSE: REMARKS BY THE FIRST LADY AT A CAMPAIGN EVENT

He put his faith in the American people. (Applause.) And as a result, today, the auto industry is back on its feet again, and more importantly, people are back at work again, earning a living. (Applause.) And remember how folks were telling Barack not to take on health care.

WHITEHOUSE: Remarks by the First Lady at a Campaign Event

Last year, after the ex-communists had softened the reforms without ditching them, Poles voted Solidarity and its friends back in again.

ECONOMIST: The ex-communist east