Correct Answer: A

Rationale: In this context, 'shifts' refers to changes or alterations in brain chemistry and electrophysiology. The word 'alterations' best captures the idea that significant changes are occurring in the brain. 'Stints' (choice B) refer to short periods of time or work, which is not the meaning intended here. 'Removals' (choice C) and 'transfers' (choice D) do not fit the context of the sentence and are not related to the changes happening in the brain as described in the extract.

Correct Answer: A

Rationale: In this context, 'shifts' refers to changes or alterations in brain chemistry and electrophysiology. The word 'alterations' best captures the idea that significant changes are occurring in the brain. 'Stints' (choice B) refer to short periods of time or work, which is not the meaning intended here. 'Removals' (choice C) and 'transfers' (choice D) do not fit the context of the sentence and are not related to the changes happening in the brain as described in the extract.

Correct Answer: B

Rationale: The author presents a positive view of vegetarianism, citing benefits and supporting evidence.

Correct Answer: A

Rationale: In this context, 'integral' means 'central' or essential. The passage discusses the debate around spanking as a method of discipline. Some parents consider it an integral part of teaching right and wrong, highlighting its central importance. Therefore, the correct answer is 'A: Central.' Choice B, 'Initial,' is incorrect as the word 'integral' does not refer to something being at the beginning of a process or sequence. Choice C, 'Trifling,' is incorrect as 'integral' implies significance and importance, opposite to being trivial. Choice D, 'Irrelevant,' is incorrect as the passage clearly states that some parents view spanking as essential, making it relevant and not irrelevant.

Correct Answer: D

Rationale: In the context of the passage, 'track' refers to a 'paved, circular path' for running or walking. The last sentence of the passage encourages people to get off the couch and onto the track, indicating a physical path for exercise. Choice A, 'Keep a record of,' is incorrect as the context does not suggest any relation to recording information. Choice B, 'A new attitude,' is unrelated to the context of exercise and fatigue reduction. Choice C, 'Follow carefully,' does not fit the context of physical activity and energy levels discussed in the passage.