zhè / tiáo / hé / yǐ / qián / jīng / cháng / dào / liú / shì / dāng / dì / yǒu / míng / de / zì / rán / qí / guān

这条河以前经常倒流，是当地有名的自然奇观。

This river used to flow backwards frequently and was a well-known natural wonder in the area.