The only two flights since then have been test s of safe ty improvement s to the fuel tank, but carr ied no major part s for the research outpost .是什么意思_The only two flights since then have been test s of safe ty improvement s to the fuel tank, but carr ied no major part s for the research outpost .在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句