请帮忙听一句英语句子You have not ( )this before.you have been hiking f

请帮忙听一句英语句子You have not ( )this before.you have been hiking f Have you been in this lab before?解释Have been 英语句子Hou long have you been like this?是什么意思? You have never been before,so not to lose Have you ever been in London before? You do not know how to HAVE YOU EXPERIENCE THIS THING BEFORE? 问：Have you bought this product before? have you read this book before? 如何回答“you have not been sick,have you ” You have not been to France,have you?的回答 How understand this.You have been my long have you been in this city?