Unit 4 Global WarmingReading What is the greenhouse made and used for?A greenhouse is made of glass and is used for growing plants,especially during cold weather.How does it work?The air inside is warm because the glass traps the heat from the sun and keeps it from escaping.This makes the greenhouse heat up and so the plants can grow throughout the cold period.What are the“greenhouse gases”?In the atmosphere surrounding the earth there are gases,which are called“greenhouse gases”,including carbo
