Quasars are so far away that they constitute the best frame of reference for measuring Earth's rotation rate.

到目前为止，类星体是测量地球自转最好的参照系。

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Quasars are so far away that they constitute the best frame of reference for measuring Earth's rotation rate.

到目前为止，类星体是测量地球自转最好的参照系。

youdao