Select the meaning of the word 'undulate' in the sentence: 'Each shiver made his muscles undulate beneath his skin.'

Correct Answer: A

Rationale: In this context, 'undulate' means to move in a smooth, wave-like motion. An undulation of muscles is a subtle, continuous rippling or rolling movement, making 'ripple' the most appropriate synonym in this sentence. 'Shake' (Choice B) is incorrect as it implies a more abrupt and irregular movement. 'Flatten' (Choice C) and 'Unknot' (Choice D) are unrelated to the smooth, wave-like motion described in the sentence.

Correct Answer: A

Rationale: The word 'permeable' refers to a material or surface that allows liquids, gases, or substances to pass through it, while screening or filtering out impurities. This makes it an appropriate descriptor for a screen or filter, which function by allowing certain elements to pass through while retaining others. Choices B, C, and D are incorrect: 'Incendiary' means causing fires, 'Exuding' means giving off or releasing, and 'Resilient' means able to withstand or recover from difficult conditions.

Correct Answer: D

Rationale: Another word for putrefy is 'rot.' Putrefy means to decay or decompose, especially through the action of bacteria. Similarly, rot refers to the process of decaying or decomposing, making it a synonymous term in this context. Choices A, B, and C are incorrect. 'Discharge' means to release or let out, 'harden' means to make or become hard, and 'panic' refers to sudden uncontrollable fear or anxiety, none of which are synonymous with putrefy.

Correct Answer: B

Rationale: Superfluous means unnecessary or more than what is needed. It refers to something that is excessive or redundant. Choice B, "Excessive," is the correct synonym for superfluous. Choices A, C, and D are incorrect. "Maximum" (Choice A) means the greatest possible amount, "Insipid" (Choice C) means lacking flavor or interest, and "Soggy" (Choice D) means soaked with liquid or water.

Correct Answer: A

Rationale: The correct answer is A: 'Makes a suggestion about.' The phrase 'suggests that' indicates that the study is proposing or indicating the possibility that vaping may have certain effects on cigarette smoking. It is not stating a fact or providing evidence, but rather making a suggestion or recommendation about the relationship between vaping and cigarette smoking. Choices B, C, and D are incorrect because the phrase 'suggests that' does not provide evidence, hint at an idea, or promote a plan, but rather presents a suggestion or possibility.