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tropic - n. the part of the world that is near the equator where the weather is very warm
cheapest – adj. not costing a lot of money
biodiversity – n. the existence of many different kinds of plants and animals in an environment
realistic – adj. able to see things as they really are and to deal with them in a practical way
monumental – adj. very great or extreme
challenge – n. a difficult task or problem : something that is hard to do
emission – n. the act of producing or sending out something (such as energy or gas) from a source
diet – n. food and drink regularly provided or consumed
scale – n. the size or level of something especially in comparison to something else
