A.I. Explanation:

Correct answer: civilization

Explanation: The term 'civilization' is the most appropriate choice as it refers to a complex society characterized by urban development, social stratification, and cultural achievements, which aligns perfectly with the context of the Mayan era. The other options do not encapsulate the full scope of the Mayan achievements and societal structure.

Meaning: 'Civilization' refers to a society that has developed a high level of culture, government, and industry, particularly in the context of the Mayan people during their Classic era.

Wrong options:

• community: While 'community' refers to a group of people living in the same area, it lacks the broader implications of culture and societal complexity that 'civilization' conveys.
• society: 'Society' is a general term for a group of individuals, but it does not specifically denote the advanced cultural and structural aspects that 'civilization' implies.
• class: 'Class' refers to a group of people within a society, often based on social or economic status, and does not represent the entirety of the Mayan achievements.

Correct answer: this

Explanation: The word 'this' is used to refer to something that is close in time or space, making it suitable for discussing the immediate context of the events being described. It indicates a specific situation that is currently being analyzed, which fits well with the sentence structure.

Meaning: 'This' is a demonstrative pronoun used to refer to a specific thing or situation that is nearby or currently relevant.

Wrong options:

• that: 'That' is used to refer to something more distant in time or space, which does not fit the immediacy of the context here.
• then: 'Then' indicates a time in the past and does not serve as a pronoun to refer to the situation being discussed.
• those: 'Those' is a plural demonstrative pronoun, which does not match the singular context of the situation being referred to.

Correct answer: period

Explanation: The term 'period' is the most fitting choice as it denotes a specific duration of time characterized by particular events, which aligns with the context of a drought leading to famine. It captures the essence of a defined timeframe in historical analysis.

Meaning: A 'period' refers to a length of time during which certain events or conditions occur, making it suitable for discussing the duration of the drought.

Wrong options:

• time: While 'time' is a general term, it does not convey the specificity of a defined duration that 'period' does.
• range: 'Range' implies a variety or extent, which does not accurately describe the singular event of drought leading to famine.
• phase: 'Phase' suggests a stage in a process, which is less appropriate than 'period' for discussing a historical timeframe.

Correct answer: research

Explanation: The word 'research' is the most appropriate choice as it refers to the systematic investigation into a subject, which aligns with the context of geological studies supporting the claim of a drought. It indicates a formal and scientific approach to understanding the past.

Meaning: 'Research' refers to the careful study and investigation of a subject to discover new information or reach new conclusions.

Wrong options:

• test: 'Test' implies a trial or experiment, which does not encompass the broader and more systematic nature of the investigation implied by 'research.'
• examination: 'Examination' suggests a close inspection but lacks the comprehensive and investigative connotation that 'research' carries.
• exploitation: 'Exploitation' refers to the act of using something for one's advantage, which does not fit the context of studying geological evidence.