Correct Answer: D

Rationale: The title 'The Debate over Barefoot Running' captures the main discussion in the passage.

Correct Answer: D

Rationale: The author does not conclude choice A, and the passage does not deal with choice B. Only one paragraph deals with the topic in choice C. The passage is mostly about the pros and cons of barefoot running, making D the best choice

Correct Answer: A

Rationale: The main idea is that super foods are low in calories but provide essential nutrients with significant health benefits.

Correct Answer: C

Rationale: The main idea of the passage is that getting the proper amount of uninterrupted sleep plays a major role in the development of muscle. The passage emphasizes how muscle growth occurs during rest periods following a workout, with sleep being a critical time for muscle fiber rebuilding. The connection between sleep, human growth hormone (HGH) release, and muscle development is highlighted. Choice A is incorrect because while the passage mentions the link between inadequate sleep and obesity due to altered appetite hormones, the main focus is on muscle development. Choice B is incorrect because although the passage discusses HGH release during deep sleep, the primary emphasis is on the role of uninterrupted sleep in muscle development. Choice D is incorrect because while the passage acknowledges that developing muscle growth is essential for health as we age, the key point is the significance of uninterrupted sleep in the muscle development process.

Correct Answer: D

Rationale: The correct answer is D. The passage focuses on describing sickle-cell anemia as a painful and inherited disease. It details how the abnormal sickle-shaped cells cause symptoms like bone pain, fever, and fatigue. While bone pain is mentioned as a symptom, it is not the main idea of the passage. Choice A is incorrect. Choice B, which mentions oxygen transport, is not the main idea but a general concept. Choice C, stating genetically inherited diseases affect thousands, is too broad and does not focus on the specifics of sickle-cell anemia. Therefore, D is the most precise choice.