邮戳

yóu chuō wéi píng zhèng

邮戳为凭证。

Postmark serves as a proof.

zài xìn shang gài shang yóu chuō

在信上盖上邮戳

postmark a letter

xìn shang gài zhe rì qī yóu chuō

信上盖着日期邮戳。

There is a date stamped on the letter.

yī fēng gài zhe běi jīng yóu chuō de xìn

一封盖着北京邮戳的信

a letter postmarked Beijing

zhè fēng xìn shang gài yǒu yóu chuō

这封信上盖有邮戳。

This letter is postmarked.