How much is it?询问价格 — 英语选择题
题目
在水果店里，Tom买了一个西瓜，店员说："It's twelve yuan." Tom又买了三个苹果，每个苹果3元。Tom一共付给店员30元。根据情境，如果要问西瓜加一个苹果的总价，下面哪句是对的，答案是多少钱？A. How much is it? It's 15 yuan. B. How much are they? They're 21 yuan. C. How much is it? It's 20 yuan. D. How much are they? They're 18 yuan.