Correct Answer: B

Rationale: Overturn in this context means invalidate, referring to whether the study is strong enough to change existing guidelines.

Correct Answer: B

Rationale: Basketball is not listed as a low-impact sport in the extract provided; the others (martial arts, yoga, and weight lifting) are considered low-impact activities. The extract mentions that students can participate in low-impact sports like yoga, martial arts, and weight lifting in modern PE classes, emphasizing their benefits and the focus on general skills. Basketball, on the other hand, is not included in the list of low-impact sports mentioned in the extract, making it the correct answer. This demonstrates the importance of understanding the difference between high-impact and low-impact sports for maintaining fitness and health.

Correct Answer: B

Rationale: In this context, "watchdog" refers to a guard or overseer, specifically relating to Lifewings Partners' mission of ensuring safety and preventing medical errors. The organization acts as a monitor in healthcare settings, which aligns with the definition of a watchdog, confirming that option B is correct.

Correct Answer: A

Rationale: The passage suggests that obesity and its related health issues contribute to lower life expectancy, implying obesity is detrimental to a long life.

Correct Answer: A

Rationale: The best summary of the passage emphasizes the importance of certain fats, particularly unsaturated fats, for bodily function. It highlights that after years of negative publicity, experts now recognize the significance of consuming fats for overall health. The passage discusses how fat is essential for cell health, vitamin absorption, and various bodily functions. It also distinguishes between healthier unsaturated fats like olive oil and detrimental trans fats. Choice B is not the best summary as it focuses more on the choice between unsaturated and saturated fats rather than the overall importance of fats. Choice C is incorrect as the passage doesn't solely attribute functioning metabolisms to fat calories. Choice D is not the best summary as it only briefly mentions saturated fats and fried foods, missing the broader context provided in the passage.