Lignohumus
木素腐殖質
??? 情景例句
Is something the matter, Grandpa?
怎么了，爺爺？
If you trust before you try,you may repent before you die.
不經考驗就依賴，不到瞑目便的悔。
He's been there for over two years. He's been there since two years ago.
他到校有兩年多時間了。他兩年前就到那兒學習了。