As for the gravel swept into the grottoes,it is exactly like a large sheet of sand paper that is at all times rapidly rubbing the fragile murals.是什么意思_As for the gravel swept into the grottoes,it is exactly like a large sheet of sand paper that is at all times rapidly rubbing the fragile murals.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句