Meaning: 'Variability' means the quality of being varied or diverse, particularly in genetic traits among a population.

Wrong options:

• integrity: Integrity refers to the state of being whole or undivided, which does not apply to genetic differences in this context.
• conformity: Conformity implies compliance with standards or norms, which is not relevant to the concept of genetic diversity.
• stability: Stability suggests a lack of change or variation, contradicting the idea of genetic diversity.

Correct answer: across

Explanation: The word 'across' is appropriate as it indicates a distribution over a wide area, which is necessary to describe the study's analysis of genomes from various locations on the continent.

Meaning: 'Across' means from one side to the other or throughout an area, indicating the widespread nature of the study's sample.

Wrong options:

• at: 'At' suggests a specific point or location, which does not convey the breadth of the study's geographical scope.
• with: 'With' implies accompaniment or association, which does not fit the context of sampling from different locations.
• off: 'Off' indicates separation or removal, which is not relevant to the context of analyzing genomes across a continent.

Correct answer: date

Explanation: The word 'date' is suitable as it refers to a specific point in time, which aligns with the context of determining when genetic separation occurred.

Meaning: 'Date' refers to a particular day or time when an event happened, in this case, the genetic separation between populations.

Wrong options:

• analysis: 'Analysis' refers to the examination of data, which does not fit the context of identifying a time frame for genetic separation.
• location: 'Location' refers to a place, which does not pertain to the timing aspect of genetic separation.
• feature: 'Feature' implies a characteristic or attribute, which is not relevant to the concept of time in this context.

Correct answer: made

Explanation: The word 'made' is correct as it indicates the composition of a group, fitting grammatically and contextually to describe how Indigenous Australians were formed from distinct nations.

Meaning: 'Made' means to be composed of or formed from, indicating the diverse nations that constituted Indigenous Australians.

Wrong options:

• set: 'Set' implies placing something in a specific position, which does not convey the idea of composition in this context.
• broken: 'Broken' suggests something that is damaged or not functioning, which is not relevant to the context of cultural composition.
• laid: 'Laid' typically refers to placing something down, which does not fit the context of describing the makeup of a population.

Correct answer: expectancy

Explanation: The term 'expectancy' is appropriate as it refers to the anticipated duration of life, fitting the context of health and well-being comparisons between populations.

Meaning: 'Expectancy' refers to the expected duration of life, particularly in terms of life expectancy in health studies.

Wrong options:

• level: 'Level' refers to a position or standard, which does not relate to the concept of life duration.
• assurance: 'Assurance' implies a guarantee or confidence, which is not relevant to the context of life duration.
• rate: 'Rate' refers to a measure or frequency, which does not specifically address the concept of life duration as 'expectancy' does.