A.I. Explanation:

Correct answer: aroused

Explanation: The word 'aroused' fits grammatically as it is the past tense of 'arouse,' which is appropriate here to indicate that the interest was stimulated in the past. Contextually, it aligns with the idea of a wish for self-adornment leading to an increase in interest among Stone Age people.

Meaning: 'Aroused' means to awaken or stimulate a feeling or interest, in this case, the interest in metals.

Wrong options:

• enlivened: 'Enlivened' means to make something more entertaining or lively, which does not fit the context of stimulating interest in a specific subject.
• cultivated: 'Cultivated' implies nurturing or developing something over time, which does not accurately describe the sudden interest in metals.
• incited: 'Incited' suggests provoking or stirring up, which carries a more negative connotation and does not fit the neutral context of interest.

Correct answer: idling

Explanation: The word 'idling' fits grammatically as it is a gerund that describes the action of wasting time without any specific purpose. Contextually, it aligns with the scenario of waiting by the river, suggesting a relaxed state of doing nothing.

Meaning: 'Idling' means to spend time doing nothing or being inactive, which fits the context of waiting for a fish.

Wrong options:

• passing: 'Passing' implies moving by or through, which does not convey the sense of inactivity required in this context.
• occupying: 'Occupying' suggests being engaged in an activity, which contradicts the idea of waiting idly.
• employing: 'Employing' means to use something for a purpose, which does not fit the context of simply waiting.

Correct answer: bed

Explanation: The word 'bed' fits grammatically as a noun that refers to the bottom of a river. Contextually, it makes sense as it describes where the shiny yellow pebble was found, aligning with the natural setting of the river.

Meaning: 'Bed' in this context refers to the ground or bottom of a river where pebbles and stones are found.

Wrong options:

• form: 'Form' refers to the shape or structure of something, which does not relate to the physical location of the pebble.
• edge: 'Edge' implies the border or boundary, which does not accurately describe the area where the pebble was located.
• work: 'Work' does not fit contextually as it refers to effort or labor, which is unrelated to the natural setting of the river.

Correct answer: conjecture

Explanation: The word 'conjecture' fits grammatically as a verb that means to form an opinion or theory without firm evidence. Contextually, it aligns with the idea of making an educated guess about how gold entered the lives of primitive people.

Meaning: 'Conjecture' means to guess or speculate about something based on incomplete information.

Wrong options:

• reform: 'Reform' means to make changes to improve something, which does not fit the context of making a guess about historical events.
• adjust: 'Adjust' implies making a change to something to improve it, which does not relate to forming an opinion or theory.
• grade: 'Grade' refers to a level of quality or rank, which does not fit the context of hypothesizing about the past.

Correct answer: Given

Explanation: The word 'Given' fits grammatically as a preposition that introduces a condition or fact. Contextually, it sets up the premise that the malleability of the metal is a known fact that influences the following statement.

Meaning: 'Given' means considering or taking into account a particular fact or situation.

Wrong options:

• Brought: 'Brought' is a verb that implies carrying something to a place, which does not fit the context of establishing a condition.
• Said: 'Said' is a past tense verb that refers to expressing something verbally, which does not fit the context of introducing a premise.
• Taken: 'Taken' is a verb that implies receiving or capturing something, which does not align with the conditional structure needed here.

Correct answer: pursued

Explanation: The word 'pursued' fits grammatically as the past tense of 'pursue,' indicating an action that was actively undertaken. Contextually, it aligns with the idea of searching for copper ores with determination.

Meaning: 'Pursued' means to follow or chase after something, in this case, the search for copper ores.

Wrong options:

• appointed: 'Appointed' means assigned to a position or task, which does not fit the context of actively searching for something.
• got: 'Got' is a colloquial term for obtaining something, which lacks the active connotation needed in this context.
• supported: 'Supported' means to provide assistance or backing, which does not convey the idea of actively searching or chasing after copper.