Their defining features are an amino group (a nitrogen and two hydrogens) and a carboxylic acid group (a carbon, two oxygens and a hydrogen), both attached to the same carbon.是什么意思_Their defining features are an amino group (a nitrogen and two hydrogens) and a carboxylic acid group (a carbon, two oxygens and a hydrogen), both attached to the same carbon.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句