Have you ever been in a greenhouse ? It's a building in which people grow plants, even in cold weather. Greenhouse roofs and walls are made of glass or plastic. These transparent materials let a lot of sunlight shine into the building.
Have you ever been in a greenhouse ? It's a building in which people grow plants, even in cold weather. Greenhouse roofs and walls are made of glass or plastic. These transparent materials let a lot of sunlight shine into the building.
