问题描述：
为什么下面的一个句子中的buy要加ing
what is the difference between buying clothes in a store and buying them in the steet.（可能有的词拼错,）
what is the difference between buying clothes in a store and buying them in the steet.（可能有的词拼错,）
问题解答：
我来补答展开全文阅读