珀西对兰花的痴迷可以回溯到1951年。Percy's enchant-ment with orchids dates back to 1951.这个城镇的历史可回溯到中世纪.The history of the town dates back to the Middle Ages.注意:我们还要回溯所忽略的字符.Note that we back up over ignored characters too....

“回溯”的拼音为：huí sù...

“回溯”的英语可以翻译为：ecall，look back upon，backdate，remount，remount to ...