A. After this street became a commercial street, pedestrians flowed from morning to night. ) )。 [Explanation: Endless flow is an idiom that means that it is as continuous as a river.] This sentence was very appropriate to describe the endless flow of pedestrians from morning to night. The word " bustling " was used to describe a prosperous business that lacked a continuous flow of people. Answer:A. After this street became a commercial street, pedestrians flowed from morning to night. ) )。