Which greenhouse gas is produced by refrigeration and air conditioning systems?

carbon dioxide
fluorinated gas
nitrous oxide
methane

The specific department of health and human services (hhs) regulations that apply to research with children are known as: subpart b: additional protections for children involved as subjects in researchsubpart a: the common rulesubpart d: additional protections for children involved as subjects in researchsubpart c: protections for children in research

How did dynasties end and how did new ones start?

What is the role of communication within groups of people with different backgrounds?