Meaning: 'Rise' refers to an increase or growth, particularly in the context of the emergence and expansion of civilizations.

Wrong options:

• density: 'Density' refers to the degree of compactness of a substance, which does not fit the context of civilizations developing; it implies a measurement rather than a growth.
• climb: 'Climb' is a verb that suggests an action of moving upwards, which does not fit grammatically as a noun in this context.
• work: 'Work' is a noun that refers to effort or labor, which does not convey the idea of growth or increase in civilizations.

Correct answer: interest

Explanation: The word 'interest' is appropriate here as it indicates a significant level of curiosity or concern regarding diets, fitting the context of the sentence where a noun is needed to describe people's engagement with dietary trends.

Meaning: 'Interest' means a feeling of wanting to know or learn about something, in this case, diets like paleo.

Wrong options:

• surplus: 'Surplus' refers to an excess amount of something, which does not fit the context of people's engagement or curiosity about diets.
• disregard: 'Disregard' means to ignore or pay no attention to something, which is the opposite of showing interest.
• approval: 'Approval' indicates a positive judgment or acceptance, which does not convey the idea of curiosity or engagement with diets.

Correct answer: overturning

Explanation: The word 'overturning' fits grammatically as a gerund that describes the action of reversing or changing previous guidelines, aligning well with the context of studies challenging existing dietary advice.

Meaning: 'Overturning' means to reverse or invalidate something, particularly in the context of changing dietary guidelines based on new research.

Wrong options:

• calling: 'Calling' is a gerund that implies naming or summoning, which does not fit the context of changing dietary guidelines.
• determining: 'Determining' suggests establishing or concluding something, which does not convey the idea of reversing previous guidelines.
• expecting: 'Expecting' indicates anticipation or belief about something happening, which does not relate to the action of changing or reversing guidelines.

Correct answer: locally

Explanation: The word 'locally' is an adverb that describes the sourcing of foods from nearby areas, fitting the context of the sentence where an adverb is needed to modify the verb 'sourced.'

Meaning: 'Locally' means from the nearby area, emphasizing the trend of sourcing food from local producers.

Wrong options:

• basically: 'Basically' is an adverb that simplifies or summarizes a statement, which does not fit the context of describing the sourcing of foods.
• local: 'Local' is an adjective that describes something related to a particular area, but it does not fit grammatically as it needs to modify a noun, not a verb.
• basic: 'Basic' is an adjective that refers to something fundamental or simple, which does not convey the idea of sourcing food.