About HK Tram

Hi,
When a tram comes, it makes a sound of " ding ding" as the sound
from a car horn just to remind passengers of its coming.
When the tram is ready to leave the station, it makes the " ding ding" sound too just to let all passengers or other people know it is going to run.
They are cool, polite and nostalgic, much more pleasant than the honk of a car or bus.
886

這是甚麼年級的問題?
如果是低年級,我建議答案如下:
The sound of 'ding ding' to remind a passenger the door soon to shut. this sound would occurrence the door want to close.