He believes that as far back as 30,000 B.C., hunters may have used a system of notation, engraved on bone and stone, to mark phases of the Moon.

他认为，远在公元前30,000年以前，猎人可能会用一套刻在骨头和石头上的符号系统来标记月相。

youdao

Bill Stone: in my opinion, within our lifetimes, microbiological life will be shown to exist either on Mars or on Europa, or some other outer planet's watery moon.

比尔·斯通：在我看来，在我们的有生之日，将会看到微生物在火星、“欧罗巴”或一些外星的冰质卫星上存在。

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This means the moon can act as a stepping stone to other planets.

这就意味着月球可以充当一个去其他行星的中转站。

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That budget would end funding for the Constellation program, which would have returned U.S.astronauts to the moon as a stepping stone to Mars.

VOA: standard.2010.04.15

The Taj Mahal in India has been called a poem in stone, a moon-white dream, a tear on the face of humanity.

NPR: A Pilgrimage to the Taj Mahal, a 'Poem in Stone'

Mr Duncan starts with a Stone Age astronomer who observed the phases of the moon, and marked them by carving notches on an eagle's bone.

ECONOMIST: Late for the date

The Moon was just supposed to be a stepping stone to Mars.

BBC: Applicants wanted for a one-way ticket to Mars