【正确答案】
(Student's sample)
Politeness is never a past thing. In China, there are many advertisements, they tell people to pay attention to their manners. People learn politeness when young in other countries, too. The bad behavior I think is not queuing when getting on a bus.
(Improved sample)
Politeness will never become a thing of the past. In China, there are many public advertisements on the streets telling people to pay attention to their manners. And in many countries, people learn to be polite when in school. The rudest behavior, I think, is to hop on a bus without queuing.