Meaning: 'During' means 'throughout the duration of' and is used to indicate that something happens at the same time as another event.

Wrong options:

• Wherever: 'Wherever' indicates a location and does not fit the temporal context required here.
• However: 'However' is a conjunction used to contrast ideas, which does not apply to the context of describing a time frame.
• Therefore: 'Therefore' indicates a conclusion or result, which does not align with the context of describing an event occurring in time.

Correct answer: represent

Explanation: 'Represent' is the correct choice as it indicates that the bones are a significant example of the skeleton, fitting both grammatically and contextually within the sentence.

Meaning: 'Represent' means to stand for or symbolize something, in this case, the bones symbolizing a large portion of the skeleton.

Wrong options:

• grateful: 'Grateful' describes a feeling of thankfulness and does not fit the context of describing what the bones do.
• swept: 'Swept' implies a physical action of moving something, which does not apply to the context of bones being a part of the skeleton.
• produce: 'Produce' suggests creating or generating something, which does not accurately describe the relationship of the bones to the skeleton.

Correct answer: upset

Explanation: 'Upset' is the correct choice as it indicates a significant change or disturbance in understanding, fitting the context of how the discovery altered perceptions of evolution.

Meaning: 'Upset' means to disturb or change something significantly, in this case, our understanding of evolution.

Wrong options:

• reset: 'Reset' implies starting over, which does not accurately convey the nature of the change in understanding.
• handset: 'Handset' refers to a device and is irrelevant in this context of discussing understanding.
• setup: 'Setup' refers to the arrangement of something and does not fit the context of changing understanding.

Correct answer: upright

Explanation: 'Upright' is the correct choice as it describes the position of walking, fitting grammatically and contextually with the sentence's focus on posture.

Meaning: 'Upright' means standing or walking with the body straight up, which is relevant to the discussion of Lucy's walking ability.

Wrong options:

• right: 'Right' refers to direction or correctness and does not fit the context of describing a walking position.
• write: 'Write' is a verb related to composing text and is irrelevant in this context.
• handwritten: 'Handwritten' describes something written by hand and does not relate to the context of walking.

Correct answer: intellectually

Explanation: 'Intellectually' is the correct choice as it refers to mental capacity or intelligence, fitting the context of comparing cognitive abilities.

Meaning: 'Intellectually' means relating to the intellect or mental capacity, which is relevant when discussing advanced capabilities.

Wrong options:

• entitled: 'Entitled' refers to having a right to something and does not fit the context of discussing intelligence.
• selected: 'Selected' implies a choice made and does not relate to the context of cognitive advancement.
• actually: 'Actually' is an adverb used to emphasize truth but does not fit the context of discussing levels of intelligence.