Here is the receipt. 这是收据。

Here is the receipt.Please keep it.Sir. 这是收据，请拿好，先生。

What for? 这是干什么用的？

It's required when you draw back the duties. 退税的时候需要。

Here is your tax-refund form. 这是您的退税单。

Here is your tax-refund form. Please keep it.Sir. 这是您的退税单。请保存好，先生。

What for? 干什么用？

You can draw back the tax paid at the customs with this form. 你开业凭这张表格在海关取回所付税款。

B：Oh,I see.Thank you! 哦，明白了，谢谢你！