Each letter is date-stamped so we know when it came in.每封信都盖有日期戳,所以我们知道信是什么时候到的。A date stamp inside the front cover of a library book shows when it should be returned.图书馆藏书封面上的日期戳标明了应还书日期。He stamped the date on the letter. = He stamped the letter with the date.他在信上盖上日期戳。