To show why it is that the Moon changes shape ask someone to hold up a white ball and walk round a light with it.

为了表示为什么月亮改变形状，让人拿着一个白色的球然后绕着灯走。

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To show why it is that the Moon changes shape ask someone to hold up a white ball and walk round a light with it.

为了表示为什么月亮改变形状，让人拿着一个白色的球然后绕着灯走。

youdao