liè chē / mén / bì shàng / yǐ hòu / zhàn tái / shàng / de / chéng kè / cái / kāi shǐ / xiàng / chū kǒu / zǒu qù

列车门闭上以后，站台上的乘客才开始向出口走去。

Only after the train doors closed did the passengers on the platform begin walking toward the exit.