How does the atmosphere act as a blanket?

(N/A) The atmosphere acts as a blanket by performing the following functions:
$(a)$ It keeps the average temperature of the Earth fairly constant during day time and even during the course of the whole year.
$(b)$ It prevents a sudden increase in the temperature during day time.
$(c)$ It slows down the escape of heat from the surface of the Earth into outer space during night time.