When Mr. Zheng returned from abroad a few years ago, the year of his birth was exactly 33 times his age. From this we can know the year of Mr. Zheng's birth.
郑老师前几年从国外回国时，他出生的公元年份恰好是他年龄的33倍，由此可知郑老师的出生年份是多少．
<result>1_947</result>