Given a scientific passage and an answer, generate a question for the given answer.
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Question: Passage: Like a blanket on a sleeping person, greenhouse gases act as insulation for the planet. The warming of the atmosphere is because of insulation by greenhouse gases. Greenhouse gases are the component of the atmosphere that moderate Earth's temperatures. Answer: insulation

Answer: Like a blanket on a sleeping person, greenhouse gases act as what for the planet?

Question: Passage: Infectious diseases are diseases that spread from person to person. They are caused by pathogens such as bacteria, viruses or fungi. What can you do to avoid infectious diseases? Eating right and getting plenty of sleep are a good start. These habits will help keep your immune system healthy. With a healthy immune system, you will be able to fight off many pathogens. The next best way is to avoid pathogens. Though this is difficult, there are steps you can take to limit your exposure to pathogens. Answer: immune system

Answer: What system is responsible for defending your body against sickness?

Question: Passage: Some elements have been known for centuries (gold, silver, iron, copper, among others) while others have been created in the lab only within the last several years. Most elements do not exist as such in nature. They are so reactive that they can be found only in combination with other materials. Answer: condensation

Answer:
What is the term for the process in which water vapor changes to tiny droplets of liquid water?