Meaning: 'Stood' means to be in an upright position, suggesting that humans were present and aware of their surroundings during a pivotal moment in history.

Wrong options:

• wandered: 'Wandered' implies movement and exploration, which does not fit the context of being on the edge of a change as it suggests a lack of focus or purpose.
• thought: 'Thought' refers to the act of thinking, which does not convey the physical presence or state of being that the sentence requires.
• lay: 'Lay' suggests a horizontal position, which contradicts the imagery of humans standing at a significant moment in history.

Correct answer: control

Explanation: 'Control' is the appropriate choice as it signifies the ability to manage or influence a powerful element of nature, which aligns with the context of discovering fire and its implications for human life.

Meaning: 'Control' means to have power over something, indicating that humans gained mastery over fire, which was previously a wild and dangerous element.

Wrong options:

• share: 'Share' implies distributing something among others, which does not fit the context of gaining mastery over fire.
• confusion: 'Confusion' suggests a lack of understanding or clarity, which is contrary to the idea of gaining control over fire.
• invention: 'Invention' refers to the creation of something new, but in this context, it does not accurately describe the act of managing an existing element like fire.

Correct answer: fear

Explanation: 'Fear' is the correct answer as it directly relates to the emotional response humans had to the dangers present at night, fitting seamlessly into the context of the sentence.

Meaning: 'Fear' refers to an unpleasant emotion caused by the belief that someone or something is dangerous, highlighting the threats faced by early humans after dark.

Wrong options:

• lure: 'Lure' means to attract or entice, which does not fit the context of danger and emotional response during nightfall.
• feat: 'Feat' refers to an achievement or accomplishment, which is unrelated to the emotional state of humans in the context of danger.
• gill: 'Gill' is a respiratory organ found in fish, which is completely irrelevant to the context of human emotions and nighttime dangers.

Correct answer: shelter

Explanation: 'Shelter' is the correct choice as it refers to a place that provides protection from danger, aligning perfectly with the context of where humans would hide during the night.

Meaning: 'Shelter' means a structure that offers protection from the elements or danger, indicating the need for safety during nighttime threats.

Wrong options:

• zone: 'Zone' refers to an area or region, which does not convey the idea of a protective space that humans would seek during danger.
• horizon: 'Horizon' refers to the line where the earth's surface and the sky appear to meet, which is not relevant to the concept of safety or protection.
• aspect: 'Aspect' refers to a particular part or feature of something, which does not fit the context of a physical place for safety.