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greenhouse gas emissions –n. harmful gases, like carbon dioxide that scientists say cause global warming
mainstream – n. the ideas, beliefs or activities regarded as normal
recruiting –v. finding the right people to join an organization
solar system –n. our sun and the planets that move around it
patent –n. official document that gives a person or company the right be the only one to make or sell a product for a certain amount of time
organism –n. an individual living thing
human ancestor –n. a person who came before modern humans, one of the people from whom humans descended
