the commonest type of solidified lava; a dense dark gray fine-grained igneous rock composed chiefly of calcium-rich plagioclase feldspar and pyroxene是什么意思_the commonest type of solidified lava; a dense dark gray fine-grained igneous rock composed chiefly of calcium-rich plagioclase feldspar and pyroxene在线翻译_英语_读音_用法_例句