Meaning: 'Difficulty' refers to the state of being hard to do or accomplish, indicating that proving the connection between good looks and winning votes is not straightforward.

Wrong options:

• chance: 'Chance' implies a possibility or likelihood, which does not convey the sense of challenge needed in this context.
• reference: 'Reference' suggests mentioning or alluding to something, which does not fit the context of proving a point about beauty and voting.
• approval: 'Approval' indicates a positive response or agreement, which does not align with the idea of facing a challenge in proving a theory.

Correct answer: beholder

Explanation: The term 'beholder' is the correct choice as it refers to someone who observes or looks at something, fitting perfectly in the phrase 'beauty is in the eye of the beholder,' which is a well-known idiom. This aligns with the context of perception of beauty.

Meaning: 'Beholder' means a person who sees or looks at something, particularly in the context of appreciating beauty.

Wrong options:

• looker: 'Looker' is a less formal term for someone who looks, but it does not carry the idiomatic weight of 'beholder' in this context.
• watching: 'Watching' is a verb form that does not fit grammatically as a noun in this context, as it describes the action rather than the observer.
• waver: 'Waver' means to fluctuate or hesitate, which does not relate to the concept of observing beauty.

Correct answer: smirk

Explanation: The word 'smirk' is appropriate here as it describes a type of smile that is often smug or self-satisfied, fitting the context of discussing George Bush's facial expression. It aligns with the tone of the sentence, which contrasts different perceptions of his appearance.

Meaning: 'Smirk' refers to a smile that is often perceived as insincere or smug, suggesting a playful or ironic expression.

Wrong options:

• jerk: 'Jerk' is a noun that refers to a rude or contemptible person, which does not fit the context of describing a facial expression.
• stare: 'Stare' implies a fixed look, which does not convey the nuance of a facial expression like a smile or grin.
• rare: 'Rare' is an adjective that means uncommon, which does not apply to the context of describing a facial expression.

Correct answer: physically

Explanation: The word 'physically' fits well as it describes the aspect of assessing someone based on their physical appearance, which is the intended meaning in the context of the sentence. It complements the idea of political assessment by adding a layer of physical evaluation.

Meaning: 'Physically' refers to the aspect of someone's appearance or bodily presence, indicating that assessments include physical traits.

Wrong options:

• presently: 'Presently' means currently or at this moment, which does not relate to the assessment of physical appearance.
• scarcely: 'Scarcely' means hardly or barely, which does not fit the context of making an assessment.
• greatly: 'Greatly' implies a significant degree, which does not specifically relate to the physical aspect of assessment.