Meaning: A 'theory' is a well-substantiated explanation of an aspect of the natural world, based on a body of evidence.

Wrong options:

• provoked: 'Provoked' is a verb that indicates causing a reaction, which does not fit as a noun in this context.
• supported: 'Supported' is a verb that implies backing or assisting, which does not serve as a noun here.
• rebuff: 'Rebuff' is a noun meaning a blunt or abrupt rejection, which does not relate to the concept being introduced.
• raised: 'Raised' is a verb that means to lift or elevate, which does not fit as a noun in this context.
• backed: 'Backed' is a verb that means to support or endorse, which does not serve as a noun here.
• acceptance: 'Acceptance' is a noun that refers to the action of consenting to receive or undertake something, which does not fit the context of introducing a concept.

Correct answer: backed

Explanation: The term 'backed' is a past participle used here as a verb, indicating that the hypothesis was supported by experiments. This fits grammatically and contextually as it describes the relationship between the hypothesis and the experiments conducted.

Meaning: 'Backed' means supported or endorsed, particularly in the context of evidence or arguments.

Wrong options:

• provoked: 'Provoked' is a verb that means to incite or stimulate a reaction, which does not fit the context of supporting a hypothesis.
• supported: 'Supported' is a verb that could fit, but it is not the correct form needed here as 'backed' is the specific term used in this context.
• rebuff: 'Rebuff' is a noun meaning a rejection, which does not relate to the support of a hypothesis.
• raised: 'Raised' is a verb that means to lift or elevate, which does not fit the context of providing support.
• inference: 'Inference' is a noun that refers to a conclusion drawn from evidence, which does not fit as a verb in this context.
• acceptance: 'Acceptance' is a noun that refers to the action of agreeing to something, which does not fit as a verb here.

Correct answer: inference

Explanation: The word 'inference' is a noun that indicates a conclusion reached based on evidence and reasoning rather than direct observation. This fits grammatically as the object of the preposition 'on' and contextually as it describes the nature of Harvey's hypothesis.

Meaning: 'Inference' refers to a conclusion drawn from reasoning or evidence rather than direct observation.

Wrong options:

• provoked: 'Provoked' is a verb that means to incite a reaction, which does not fit as a noun in this context.
• backed: 'Backed' is a past participle that indicates support, which does not fit as a noun here.
• rebuff: 'Rebuff' is a noun meaning a blunt rejection, which does not relate to the concept of drawing conclusions.
• raised: 'Raised' is a verb that means to lift or elevate, which does not fit as a noun in this context.
• supported: 'Supported' is a verb that means to assist or back, which does not serve as a noun here.
• acceptance: 'Acceptance' is a noun that refers to the action of agreeing to something, which does not fit the context of reasoning.

Correct answer: provoked

Explanation: The term 'provoked' is a verb that indicates that the radical idea caused a reaction, specifically ridicule. This fits grammatically as the main verb of the clause and contextually as it describes the response to Harvey's hypothesis.

Meaning: 'Provoked' means to incite or stimulate a reaction, often negative in this context.

Wrong options:

• theory: 'Theory' is a noun that refers to a proposed explanation, which does not fit as a verb in this context.
• supported: 'Supported' is a verb that means to back or endorse, which does not fit the context of causing a reaction.
• rebuff: 'Rebuff' is a noun meaning a rejection, which does not fit as a verb here.
• raised: 'Raised' is a verb that means to lift or elevate, which does not fit the context of inciting a reaction.
• backed: 'Backed' is a verb that means to support, which does not fit the context of provoking ridicule.
• acceptance: 'Acceptance' is a noun that refers to agreeing to something, which does not fit as a verb in this context.

Correct answer: acceptance

Explanation: The word 'acceptance' is a noun that indicates the action of agreeing to or receiving something, which fits grammatically as the object of the preposition 'gained' and contextually as it describes the eventual reception of Harvey's idea in medical circles.

Meaning: 'Acceptance' refers to the action of consenting to receive or undertake something, particularly in the context of ideas or theories.

Wrong options:

• provoked: 'Provoked' is a verb that means to incite a reaction, which does not fit as a noun in this context.
• theory: 'Theory' is a noun that refers to a proposed explanation, which does not fit the context of gaining approval or agreement.
• rebuff: 'Rebuff' is a noun meaning a rejection, which does not relate to the concept of gaining approval.
• raised: 'Raised' is a verb that means to lift or elevate, which does not fit as a noun in this context.
• backed: 'Backed' is a verb that means to support, which does not serve as a noun here.
• inference: 'Inference' is a noun that refers to a conclusion drawn from evidence, which does not fit the context of gaining acceptance.