A.I. Explanation:

Correct answer: support

Explanation: The word 'support' fits grammatically as it is a verb that indicates providing assistance or sustenance, which aligns with the context of coral reefs sustaining marine life. It is in the present tense, matching the overall tense of the sentence.

Meaning: 'Support' means to provide the necessary conditions for something to exist or thrive, in this case, referring to coral reefs enabling a diverse range of marine life.

Wrong options:

• curb: Curb means to restrain or limit, which contradicts the idea of coral reefs fostering marine life.
• harvest: Harvest implies collecting or gathering, which does not fit the context of coral reefs providing a habitat.
• cultivate: Cultivate suggests preparing and using land for crops, which is not applicable to the natural ecosystem of coral reefs.

Correct answer: surprisingly

Explanation: The word 'surprisingly' serves as an adverb that modifies the entire clause, indicating that the fact about coral reefs being a favorite pursuit for divers is unexpected. It fits contextually and grammatically, as it aligns with the tone of the sentence.

Meaning: 'Surprisingly' means in a way that causes surprise or is unexpected, highlighting the contrast in the statement about divers' interests.

Wrong options:

• seemingly: Seemingly suggests an appearance but does not convey the unexpected nature of the fact, making it less fitting.
• specifically: Specifically indicates a particular detail, which does not align with the broader context of the statement about divers.
• demandingly: Demandingly implies a requirement or insistence, which does not fit the context of describing divers' interests.

Correct answer: double

Explanation: The word 'double' is a verb that indicates an increase by a factor of two, which fits the context of the sentence discussing the expected growth in the number of people relying on coral reefs. It is in the infinitive form, appropriate for the future tense of the sentence.

Meaning: 'Double' means to increase to twice the amount, referring to the anticipated rise in the number of people dependent on coral reefs.

Wrong options:

• appear: Appear suggests coming into view, which does not convey the idea of growth or increase in numbers.
• countdown: Countdown refers to a backward counting to a specific time, which is irrelevant in this context of population growth.
• unravel: Unravel means to come apart or be solved, which does not fit the context of increasing numbers.

Correct answer: start

Explanation: The word 'start' is a verb that indicates the beginning of an action or process, fitting grammatically and contextually as it suggests the initiation of arriving at frightening scenarios. It aligns with the future tense of the sentence.

Meaning: 'Start' means to begin or commence, indicating the onset of a situation or process, in this case, the frightening scenarios related to coral reefs.

Wrong options:

• end: End implies a conclusion, which contradicts the context of beginning to face new scenarios.
• stop: Stop suggests halting an action, which does not fit the context of progressing towards scenarios.
• lock: Lock means to secure or fasten, which does not convey the idea of initiating a process.