Meaning: 'Gradual' means happening slowly over a period of time, rather than suddenly.

Wrong options:

• tend: 'Tend' is a verb that indicates a tendency, which does not describe the nature of cognitive decline.
• determine: 'Determine' is a verb that means to establish or ascertain, which does not fit the context of describing decline.
• annual: 'Annual' is an adjective that refers to something occurring once a year, which is irrelevant to the context of cognitive decline.
• appeared: 'Appeared' is a verb that suggests something has come into view, which does not describe the nature of cognitive decline.
• debated: 'Debated' is a verb that refers to discussing a topic, which does not fit as it does not describe the decline itself.
• recommended: 'Recommended' is a verb that suggests advice or suggestion, which does not describe the decline.

Correct answer: debated

Explanation: The term 'debated' is appropriate here as it indicates that the benefits of multivitamins are a topic of discussion among doctors, fitting the context of differing opinions.

Meaning: 'Debated' means discussed or argued about, especially in a formal context.

Wrong options:

• tend: 'Tend' is a verb that indicates a tendency, which does not fit as it does not relate to the discussion of benefits.
• annual: 'Annual' is an adjective that refers to something occurring once a year, which is irrelevant to the context of benefits being discussed.
• appeared: 'Appeared' is a verb that suggests something has come into view, which does not fit the context of discussing benefits.
• gradual: 'Gradual' is an adjective that describes a slow process, which does not relate to the discussion of benefits.
• recommended: 'Recommended' is a verb that suggests advice or suggestion, which does not fit the context of discussing benefits.

Correct answer: recommended

Explanation: The word 'recommended' fits grammatically as it describes the action taken by doctors regarding multivitamins, indicating that they were advised for use based on previous beliefs.

Meaning: 'Recommended' means suggested or advised as a course of action.

Wrong options:

• tend: 'Tend' is a verb that indicates a tendency, which does not fit as it does not describe the action of doctors.
• annual: 'Annual' is an adjective that refers to something occurring once a year, which is irrelevant to the context of recommendations.
• appeared: 'Appeared' is a verb that suggests something has come into view, which does not fit the context of recommendations.
• gradual: 'Gradual' is an adjective that describes a slow process, which does not relate to the action of recommending.
• debated: 'Debated' is a verb that refers to discussing a topic, which does not fit as it does not describe the action of doctors.

Correct answer: tend

Explanation: The word 'tend' fits grammatically as it indicates a tendency or likelihood, which aligns with the context of people who take multivitamins having better health.

Meaning: 'Tend' means to have a tendency to do something or to be inclined towards a certain behavior.

Wrong options:

• determine: 'Determine' is a verb that means to establish or ascertain, which does not fit the context of describing health outcomes.
• annual: 'Annual' is an adjective that refers to something occurring once a year, which is irrelevant to the context of health.
• appeared: 'Appeared' is a verb that suggests something has come into view, which does not fit the context of health outcomes.
• gradual: 'Gradual' is an adjective that describes a slow process, which does not relate to the tendency of health outcomes.
• debated: 'Debated' is a verb that refers to discussing a topic, which does not fit as it does not describe a tendency.