A.I. Explanation:

Correct answer: messaged

Explanation: The word 'messaged' fits grammatically as it is the past tense of 'message,' which is appropriate for the context of the sentence where the teenager is communicating with his grandmother. It aligns with the narrative of him reaching out after being missing for years.

Meaning: 'Messaged' means to send a message, typically through electronic means, indicating that the teenager used a form of communication to contact his grandmother.

Wrong options:

• massaged: 'Massaged' refers to the act of manipulating the body with pressure, which does not fit the context of communication.
• notified: 'Notified' implies formally informing someone, which is not the casual tone of the message conveyed here.
• emailed: 'Emailed' specifically refers to sending a message via email, which is too specific and does not match the broader term 'messaged'.

Correct answer: vanished

Explanation: The word 'vanished' is the correct choice as it indicates a sudden disappearance, which is contextually appropriate for describing how Alex went missing during a holiday. It conveys the sense of being lost without a trace.

Meaning: 'Vanished' means to disappear suddenly and completely, which accurately describes the situation of the teenager going missing.

Wrong options:

• erupted: 'Erupted' suggests a sudden outbreak, typically used in the context of volcanoes or emotions, which does not apply to a disappearance.
• dissolved: 'Dissolved' implies a gradual disappearance, often used in a chemical context, and does not convey the suddenness of the situation.
• ceased: 'Ceased' means to stop or come to an end, which does not accurately reflect the act of disappearing.

Correct answer: wanted

Explanation: The term 'wanted' is appropriate here as it indicates that the pair is being sought by authorities in connection with the disappearance. It fits grammatically and contextually within the legal framework of the situation.

Meaning: 'Wanted' means being sought after by law enforcement, typically for questioning or investigation regarding a crime or incident.

Wrong options:

• desired: 'Desired' implies a wish for something, which does not fit the legal context of being sought by police.
• prized: 'Prized' suggests something valued or cherished, which is not relevant to the context of a police investigation.
• sought: 'Sought' is a synonym for 'wanted' but does not fit grammatically in this specific sentence structure.

Correct answer: within

Explanation: The word 'within' is the correct choice as it indicates a time frame, suggesting that Alex could return to the UK in a certain number of hours. It fits grammatically and contextually with the sentence's meaning.

Meaning: 'Within' means inside a certain limit or time frame, indicating that the return could happen before the end of that time period.

Wrong options:

• amid: 'Amid' suggests being surrounded by something, which does not fit the context of time.
• near: 'Near' implies proximity but does not convey the idea of a time frame as effectively as 'within.'
• beneath: 'Beneath' refers to a lower position or level, which is not relevant to the context of time.

Correct answer: concerned

Explanation: The word 'concerned' is appropriate as it describes the motorist's state of being worried about the boy's situation, fitting well in the context of the narrative. It aligns with the emotional tone of the sentence.

Meaning: 'Concerned' means feeling worried or anxious about someone or something, indicating the motorist's reaction upon spotting the boy.

Wrong options:

• engaged: 'Engaged' implies being involved or occupied, which does not fit the context of the motorist's reaction.
• alarmed: 'Alarmed' suggests a stronger reaction of fear or panic, which may not accurately reflect the situation described.
• troubled: 'Troubled' indicates a state of distress, which is similar but does not match the more neutral tone of 'concerned'.