bān / dào / yuán / què / rèn / liè / chē / yǐ / jīng / tōng / guò / hòu / cái / gǎi / biàn / le / dào / chà / de / fāng / xiàng

扳道员确认列车已经通过后，才改变了道岔的方向。

The switchman changed the points only after confirming that the train had passed.