A.I. Explanation:

Correct answer: come

Explanation: The word 'come' fits grammatically as it is the present perfect tense, indicating an action that has relevance to the present. It aligns contextually with the phrase 'has come a long way,' suggesting progress over time.

Meaning: 'Come' in this context means to reach a certain state or condition, indicating that dentistry has significantly advanced from its earlier practices.

Wrong options:

• gone: The word 'gone' implies a completed action without relevance to the present, which does not fit the context of ongoing progress in dentistry.
• been: 'Been' is used to indicate a state of existence but does not convey the idea of progress or change, making it unsuitable here.
• done: 'Done' suggests completion of an action but lacks the nuance of progress that 'come' provides, thus it does not fit the context.

Correct answer: boasts

Explanation: The verb 'boasts' is appropriate here as it conveys pride in having a notable list of clients. It fits grammatically and contextually, suggesting that Dr. Stemmer takes pride in his clientele.

Meaning: 'Boasts' means to talk with pride about something one possesses, indicating that Dr. Stemmer is proud of the famous clients he serves.

Wrong options:

• proclaims: 'Proclaims' suggests a formal announcement, which does not fit the informal context of discussing a client list.
• brags: While 'brags' implies boasting, it carries a negative connotation of arrogance, which is not suitable for the professional tone of the text.
• trumpets: 'Trumpets' also implies a loud announcement, which does not align with the more subtle and professional context of the sentence.

Correct answer: sealed

Explanation: The word 'sealed' fits well as it indicates that Dr. Stemmer keeps client names confidential. It is grammatically correct and contextually appropriate, suggesting a sense of discretion.

Meaning: 'Sealed' means to keep something closed or confidential, indicating that he does not disclose the names of his clients.

Wrong options:

• closed: While 'closed' could imply confidentiality, it lacks the nuance of intentional secrecy that 'sealed' conveys.
• glued: 'Glued' is more informal and suggests a physical attachment rather than confidentiality, making it unsuitable in this context.
• shut: 'Shut' is similar to 'closed' but is less formal and does not convey the same level of discretion as 'sealed'.

Correct answer: perception

Explanation: The word 'perception' is the most fitting as it refers to how one views or understands themselves, aligning perfectly with the context of improving one's appearance through dentistry.

Meaning: 'Perception' means the way in which something is regarded, understood, or interpreted, indicating that an improved smile can change how a person sees themselves.

Wrong options:

• observation: 'Observation' refers to the act of noticing something, which does not fit the context of self-view or self-image.
• discernment: 'Discernment' implies the ability to judge well, which is not directly related to self-image or perception in this context.
• consciousness: 'Consciousness' refers to the state of being aware, which is broader and less specific than 'perception' in this context.

Correct answer: hailed

Explanation: The word 'hailed' is appropriate as it indicates that Julia Roberts is widely recognized and praised for her smile. It fits grammatically and contextually, suggesting admiration from the public.

Meaning: 'Hailed' means to be publicly acclaimed or praised, indicating that she is celebrated for her smile.

Wrong options:

• cheered: 'Cheered' implies a more active form of support or applause, which does not fit the context of recognition in this case.
• saluted: 'Saluted' suggests a formal acknowledgment, which is less common in the context of public admiration for a celebrity's smile.
• exalted: 'Exalted' implies a high status or rank, which does not accurately convey the idea of public praise in this context.

Correct answer: material

Explanation: The word 'material' fits well as it refers to the physical substance or resources needed for a purpose, in this case, the importance of having good teeth for models. It is grammatically and contextually appropriate.

Meaning: 'Material' refers to the substance or resources needed for a specific purpose, indicating that good teeth are essential for models aiming to succeed.

Wrong options:

• stuff: 'Stuff' is informal and vague, lacking the specificity and professionalism required in this context.
• substance: 'Substance' is too broad and does not specifically relate to the context of physical attributes like teeth.
• matter: 'Matter' is also too general and does not convey the specific importance of having good teeth for models.