您好 Hello
请 I beg you pardon
谢谢 Thank you
对不起 Excuse me
再见 See you later
It is very common in China to educate the people with slogans. In this case the attention is focused on the very basic words of politeness.
I took this picture in the stairway leading up to a teahouse 茶馆 - Mahjong 麻将 place in Chengdu. Since ancient times Mahjong (majiang in Mandarin) - a game where skill, strategy and luck are involved - is a very popular in China.