It's become so iconic that attempts to change its taste in 1985—sweetening it in a move projected to boost sales—proved disastrous, with widespread anger from consumers.
2017年12月六级真题（第一套）阅读 Section C
柯林斯高阶英汉双解学习词典释义
VERB
使变甜;加糖于
If you sweeten food or drink, you add sugar, honey, or another sweet substance to it.
If you sweeten something such as an offer or a business deal, you try to make someone want it more by improving it or by increasing the amount you are willing to pay.