Correct Answer: A

Rationale: In the context of the sentence, 'volatile' means likely to change rapidly and unpredictably or evaporate quickly. When referring to liquids, volatile typically implies that the liquids are unstable and can easily change from liquid to gas. Therefore, the most appropriate meaning of 'volatile' in this sentence is 'unstable.' Choices B, C, and D are incorrect because 'abnormal' and 'lethal' do not capture the essence of rapid change or evaporation associated with volatile liquids, while 'blended' is unrelated to the characteristics of volatile liquids described in the sentence.

Correct Answer: C

Rationale: An overt symptom is a symptom that is easily noticeable or observable. It is not hidden or controlled, but rather overt and easily seen or identified by others. Therefore, the correct answer is C, 'obvious.' 'Dangerous' (choice A) does not describe the visibility of a symptom but rather its potential harm. 'Hidden' (choice B) is the opposite of overt, meaning not easily visible. 'Controlled' (choice D) does not relate to the visibility of a symptom but rather implies regulation or management.'

Correct Answer: C

Rationale: In this context, the word 'undergo' means to experience or go through a process. When someone undergoes something, it implies they are subjected to it or experiencing it. Therefore, in the sentence provided, 'experience' is the correct meaning. Choices A, B, and D are incorrect as they do not align with the idea of going through a process or experiencing something.

Correct Answer: D

Rationale: A sore with disintegration of tissue is typically referred to as an ulcer. Ulcers are open sores or wounds that can develop on the skin's surface or within the body. They can vary in size and depth and are commonly associated with conditions such as pressure ulcers, peptic ulcers, and venous ulcers. Ulcers result from the breakdown of tissue, leading to a loss of the skin or mucous membrane in that area. Choices A, B, and C are incorrect. Allergy refers to a hypersensitivity reaction, erythema is redness of the skin, and alopecia is hair loss. These conditions do not specifically involve the disintegration of tissue as seen in an ulcer.

Correct Answer: C

Rationale: In this context, the word 'accountable' means responsible. The night nursing staff is responsible for those records, meaning they are the ones who are answerable and expected to ensure proper care and maintenance of the records. Choice A, 'Receptive,' does not fit the context as it means willing to listen or accept information. Choice B, 'Notorious,' means famous or well-known, usually for something negative, which is not the intended meaning here. Choice D, 'Preoccupied with,' means to be engrossed or absorbed in something, which does not convey the meaning of being responsible as intended in the sentence.