问题描述：
过去式后怎么表示
比如这么一句话,我发现（过去式FOUDN)你们是销售这些产品的?用WE FOUND THAT YOU ARE SELLING THESE ITEMS OR YOU WERE SELLING? 谢谢
比如这么一句话,我发现（过去式FOUDN)你们是销售这些产品的?用WE FOUND THAT YOU ARE SELLING THESE ITEMS OR YOU WERE SELLING? 谢谢
问题解答：
我来补答展开全文阅读