The reason is that ventilation should be done for 10 to 15 minutes
image text translation (1)according to the concentration of carbon dioxide(2)a change in oxygen concentration(3)carbon dioxide(4)6:00 a.m(5)Close the window and after …
image text translation (1)according to the concentration of carbon dioxide(2)a change in oxygen concentration(3)carbon dioxide(4)6:00 a.m(5)Close the window and after …