How does an actual greenhouse work?

A greenhouse is a building with glass walls and a glass roof. In the daytime, sunlight shines into the greenhouse and warms the plants and air inside. At nighttime, it's colder outside, but the greenhouse stays pretty warm inside. That's because the glass walls of the greenhouse trap the Sun's heat.

Explanation:

is this from a story?

if so, can you tell which one?

~courtney

answer; depression and breathing related sleep disorder(independent);