Change the slogan

1. In the future, let's cheer loudly. Now, let's study quietly.

2. Talking in a low voice is beneficial to others as well as yourself.

Do you want others to hear you clearly? Please speak softly, whispering can make us hear each other clearly!

We are not deaf, please don't make any noise!

6. tranquility creates the beauty of harmony

7. The chairman said that it was not a good comrade who made noise.

Be polite and don't make noise