Riddle: Leah took note of all the buildings on her property. The red barn was made of red bricks; the blue shed was made of blue bricks; the black chicken coop was made of black bricks; and so on. When writing down the greenhouse, what did she say it was made of?
Answer: Glass!! If it were made of bricks, then no light would be able to reach the plants!
Source: https://riddles.com/index.php/7950