为了说明心脏如何使血液在全身循环流动，老师描述了水泵的工作原理。

To illustrate how the heart circulates blood through the body, the teacher described how a pump works.

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为了说明心脏如何使血液在全身循环流动，老师描述了水泵的工作原理。

To illustrate how the heart circulates blood through the body, the teacher described how a pump works.

youdao