1 The very low amounts of elements of heavier than hydrogen and helium in these stars indicate that they must have formed early in the history of the Galaxy, before large amounts of heavy elements wer
1 The very low amounts of elements of heavier than hydrogen and helium in these stars indicate that they must have formed early in the history of the Galaxy, before large amounts of heavy elements were created inside the initial generations of stars.
2 The recent speculation includes the possibility that the first living cells might have arisen on Mars, seeding Earth via the many meteorites that are known to travel from Mars to our planet.
3 Governments and their international agencies are these days mindful that public opinion is anything but squarely behind them.
（责任编辑:Allen）
