That would help to explain a puzzling anomaly about comets: they fall into two classes.

ECONOMIST: Unbuckling the Kuiper belt

If historical correlations are low enough, we separate two indexes into different asset classes.

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During his sophomore year, he failed two classes and got into a drunken brawl with some Georgetown University football players.

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At each level of education, from kindergarten to university, classes are now divided into tinier segments, generally composed of two to four students each.

CNN: ASIANOW - TIME Asia