Meaning: 'Activated' means to make something start working or to turn it on, in this case, referring to the motor inside the pill that begins to function when it comes into contact with stomach acid.

Wrong options:

• taken: 'Taken' implies receiving or consuming something, which does not convey the action of starting a mechanism, making it contextually inappropriate here.
• consoled: 'Consoled' means to provide comfort, which is irrelevant to the mechanical function of the motor and does not fit the context of activation.
• invested: 'Invested' refers to putting money or resources into something, which does not relate to the operation of the motor in the pill.

Correct answer: sensation

Explanation: The word 'sensation' is appropriate as it describes the feeling of fullness that the pill aims to create. It fits grammatically and contextually, as it relates directly to the effect of the vibrating pill on the stomach.

Meaning: 'Sensation' refers to a physical feeling or perception resulting from something that happens to or comes into contact with the body, in this case, the feeling of satiety after eating.

Wrong options:

• relation: 'Relation' refers to a connection or association, which does not convey the physical feeling intended in this context.
• submission: 'Submission' implies yielding or giving in, which is not relevant to the experience of fullness or satiety.
• fortune: 'Fortune' refers to luck or wealth, which is unrelated to the physical sensations experienced after eating.

Correct answer: less

Explanation: The word 'less' is grammatically correct as it is used to indicate a smaller amount of uncountable food consumed. It fits the context of the sentence, which discusses the reduction in food intake after taking the pill.

Meaning: 'Less' is used to describe a smaller quantity of something that cannot be counted individually, in this case, referring to the amount of food eaten by the pigs.

Wrong options:

• fewer: 'Fewer' is used for countable nouns, which does not apply here since 'food' is uncountable in this context.
• least: 'Least' is a superlative form indicating the smallest amount, which does not fit the comparative context of the sentence.
• fewest: 'Fewest' is also a superlative form used for countable nouns, making it inappropriate for the uncountable noun 'food'.

Correct answer: side

Explanation: The word 'side' fits grammatically and contextually as it refers to the adverse effects that can accompany medications or treatments. It is commonly used in medical contexts to describe unwanted effects.

Meaning: 'Side' in this context refers to side effects, which are unintended effects that occur in addition to the desired therapeutic effects of a drug or treatment.

Wrong options:

• back: 'Back' does not relate to effects in a medical context and does not convey the idea of adverse reactions.
• edge: 'Edge' refers to a border or margin and does not apply to the context of effects related to medications.
• surface: 'Surface' refers to the outermost layer of something and is not relevant to the discussion of side effects.