Correct Answer: D

Rationale: The breastbone is called the sternum. It is a flat bone located in the center of the chest that connects the ribs together and protects the heart and lungs. The term 'stelic' (choice A), 'steres' (choice B), and 'sterol' (choice C) are not correct terminologies for the breastbone.

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: B

Rationale: When tubes distend, they expand or become enlarged, which typically results in stretching rather than flexing, solidifying, or collapsing. Distending tubes imply an increase in size or volume, indicating a stretching or expansion effect. Therefore, the correct answer is 'stretch.' Choice A, 'flex,' is incorrect as flexing refers to bending or curling, not expanding. Choice C, 'solidify,' is incorrect as solidifying refers to becoming solid, which is not related to the expansion of tubes. Choice D, 'collapse,' is incorrect as collapsing refers to falling in or giving way, which is the opposite effect of distending.

Correct Answer: B

Rationale: The term 'flaccid' is commonly used to describe something that is limp, soft, or lacking firmness. It suggests a lack of stiffness or rigidity, often used to describe plants, muscles, or other objects that are in a drooping or loose state. Choice A 'Light-colored' is incorrect as it does not convey the meaning of flaccid. Choice C 'Uncontaminated' and Choice D 'Unusually aggressive' are also incorrect as they do not relate to the definition of flaccid.

Correct Answer: C

Rationale: The word 'impugn' means to challenge or attack the truth, integrity, validity, or honesty of something. It is not related to instilling (A), instructing (B), lamenting, or complaining (D). Impugn specifically involves questioning the accuracy or validity of a statement or argument, making choice C the correct answer.