- 对 對 prepositionto faceto face; to be opposite to
- hydroxyl groupa chemical group consisting of one hydrogen atom and one oxygen atom; also known as 氢氧基
- benzoic acidbenzoic acid (C6H5COOH)
- esterA type of organic compound formed by the reaction of an alcohol and an acid with the loss of water. Low molecular weight esters are typically fragrant liquids used as solvents or flavorings, while high molecular weight esters are solids or thick liquids found in fats and oils.