There's a standard open ticket which doesn't have any restrictions. This can be bought in advance or on the day.

有一种普通的不定期客票，没有任何限制，可以提前购买，也可以当天购买。

youdao

There's a standard open ticket which doesn't have any restrictions. This can be bought in advance or on the day.

有一种普通的不定期客票，没有任何限制，可以提前购买，也可以当天购买。

youdao