The price of a cup of coffee is lighter than ___of a glass of coke.如何使用這個答案that呢

The price of a cup of coffee is lighter than ___of a glass of coke.如何使用這個答案that呢

that.
一樓解釋得蠻好的.
同理:The milk here is cheaper than that of the other supermaket.
The population of China is lager than that of the United States.
that所代替的都是前面的拿來做比較的名詞,避免重複使用.