Big Bang nucleosynthesis begins about one second after the Big Bang, when the universe has cooled down sufficiently to form stable protons and neutrons, after baryogenesis.是什么意思_Big Bang nucleosynthesis begins about one second after the Big Bang, when the universe has cooled down sufficiently to form stable protons and neutrons, after baryogenesis.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句