The scientists determined that the depression was a volcanic vent, and the bright ring around it was pyroclastic, remnants of lava that had been spewed outward, much like a volcanic fountain on Earth.是什么意思_The scientists determined that the depression was a volcanic vent, and the bright ring around it was pyroclastic, remnants of lava that had been spewed outward, much like a volcanic fountain on Earth.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句