"Principal~The flag outside today is purple; today is red; today is ......" Some children noticed that the air quality flags at the school entrance are placed in different colors this week and asked the principal curiously why the flags are different these days. "What color is the flag? "Purple." "See the emoticon on the flag?" "Oh! "Two drops of sweat, wearing a mask with a scary picture on it." "So do you think this emoticon looks happy or uncomfortable?

Flag Color Preventive Measures Green Teachers and students of sensitive groups should take the initiative to pay attention to the state of air quality according to their individual physical condition and symptoms. Yellow Primary protection: 1. Enhance students, children and staff to obtain information on air pollution and health protection. 2. 2. teachers and students with cardiac, respiratory and cardiovascular diseases should consider reducing the amount of air pollution when they feel the symptoms.