They may have been a source of part of the atmosphere of the terrestrial planets, and they are believed to have been the planetesimal-like building blocks for some of the outer planets and their satellites.是什么意思_They may have been a source of part of the atmosphere of the terrestrial planets, and they are believed to have been the planetesimal-like building blocks for some of the outer planets and their satellites.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句