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*¡¡There¡¡could¡¡have¡¡been¡¡none¡£¡¡We're¡¡very¡¡lucky¡¡that¡¡there¡¡is¡¡such¡¡a¡¡world¡¡study¡£¡¡The¡¡others¡¡ill¡¡have¡¡too¡¡much¡¡hydrogen£»¡¡or¡¡not¡¡enough£»¡¡or¡¡no¡¡atmosphere¡¡at¡¡all¡£

No¡¡world¡¡is¡¡a¡¡perfect¡¡replica¡¡of¡¡any¡¡other£»
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