Meaning: 'Core' refers to the central or most essential part of something, indicating that class is a crucial element in understanding British society.

Wrong options:

• gist: 'Gist' refers to the main point or essence of something, but it lacks the connotation of being a central part, making it less suitable here.
• substance: While 'substance' can imply importance, it does not convey the idea of being the central element as effectively as 'core'.
• base: 'Base' suggests a foundation but does not capture the idea of being the most important aspect, making it less appropriate in this context.

Correct answer: inexhaustible

Explanation: The term 'inexhaustible' is appropriate as it describes something that cannot be exhausted or depleted, fitting the context of class being a never-ending topic of discussion. It also aligns with the overall tone of the passage, which suggests a deep and ongoing exploration of class.

Meaning: 'Inexhaustible' means something that cannot be used up or exhausted, indicating that the topic of class is vast and always relevant.

Wrong options:

• infallible: 'Infallible' means incapable of making mistakes, which does not fit the context of class discussions being endless or abundant.
• indefatigable: 'Indefatigable' refers to someone who persists tirelessly, which does not directly relate to the nature of the subject being discussed.
• indelible: 'Indelible' means something that cannot be removed or forgotten, but it does not convey the idea of an ongoing discussion as effectively as 'inexhaustible'.

Correct answer: spot

Explanation: The verb 'spot' is correctly used here as it means to see or notice something, which fits the context of identifying a bowler hat or cloth cap in London. It is grammatically correct and contextually appropriate for the action described.

Meaning: 'Spot' means to see or notice something, especially something that is not easily visible, which aligns with the difficulty of identifying class insignia.

Wrong options:

• glance: 'Glance' implies a quick look, which does not convey the act of noticing something specific as effectively as 'spot'.
• speer: 'Speer' is not a standard English word and does not fit grammatically or contextually in this sentence.
• scan: 'Scan' suggests a more thorough examination, which does not match the casual observation implied by 'spot'.

Correct answer: come

Explanation: The verb 'come' fits well in this context as it indicates the emergence or occurrence of class distinctions, aligning with the idea of when class becomes relevant. It is grammatically correct and contextually appropriate for the sentence.

Meaning: 'Come' in this context means to occur or to become apparent, indicating when class distinctions are recognized.

Wrong options:

• fall: 'Fall' implies a sudden drop or decline, which does not fit the context of class distinctions appearing or becoming relevant.
• break: 'Break' suggests a disruption, which does not align with the idea of class distinctions coming into play.
• arise: 'Arise' could fit but does not convey the same sense of occurrence as 'come', making it less suitable.

Correct answer: reinforces

Explanation: The verb 'reinforces' is appropriate as it means to strengthen or support an idea, which fits the context of American perceptions of class in Britain. It is grammatically correct and logically consistent with the sentence's meaning.

Meaning: 'Reinforces' means to strengthen or support an idea, indicating that what Americans see or read about class in Britain strengthens their impression of class divisions.

Wrong options:

• props: 'Props' is a noun that refers to support or assistance, which does not fit grammatically as a verb in this context.
• subsidizes: 'Subsidizes' means to support financially, which does not align with the context of reinforcing an impression.
• clinches: 'Clinches' implies securing or confirming something, which does not convey the idea of strengthening an impression as effectively as 'reinforces'.

Correct answer: between

Explanation: The preposition 'between' is correctly used here to indicate a relationship involving two distinct entities, which fits the context of separate classes. It is grammatically correct and contextually appropriate for the sentence.

Meaning: 'Between' refers to the space or relationship separating two entities, indicating the distinction between classes.

Wrong options:

• amid: 'Amid' suggests being surrounded by or in the middle of something, which does not fit the context of contrasting classes.
• midway: 'Midway' implies being in the middle of something, which does not convey the idea of separation as effectively as 'between'.
• halfway: 'Halfway' suggests a point that is equidistant from two ends, which does not align with the concept of distinct classes.