Correct Answer: B

Rationale: The correct answer is B. The passage highlights that damage to the limbic system, specifically the amygdala, can lead to passivity and lack of aggression. This is supported by the statement that patients with trauma or damage to the amygdala exhibit a complete absence of aggression. Thus, a stroke causing severe tissue damage in the limbic system, including the amygdala, can result in persistent passivity and imperturbability. Choices A, C, and D are incorrect because they do not directly relate to damage in the limbic system, which is specifically mentioned in the passage as the cause of the described behaviors.

Correct Answer: B

Rationale: The correct answer is B. The passage highlights that damage to the limbic system, specifically the amygdala, can lead to passivity and lack of aggression. This is supported by the statement that patients with trauma or damage to the amygdala exhibit a complete absence of aggression. Thus, a stroke causing severe tissue damage in the limbic system, including the amygdala, can result in persistent passivity and imperturbability. Choices A, C, and D are incorrect because they do not directly relate to damage in the limbic system, which is specifically mentioned in the passage as the cause of the described behaviors.

Correct Answer: C

Rationale: The main idea of the passage is that innovations and improvements in bicycle design have made bicycles one of the most popular means of recreation and transportation worldwide. The passage outlines the evolution of bicycles from their early designs to the modern versions, emphasizing how these changes have contributed to their popularity. Choice A is incorrect because it focuses only on the current status of bicycles, while the main idea encompasses the evolution and improvements in design. Choice B is incorrect as it mentions the invention of the first modern bicycle but does not address the overall impact of innovations on bicycle popularity. Choice D is incorrect as it simply states a fact without capturing the essence of the passage, which is about the impact of design improvements.

Correct Answer: C

Rationale: The mention of impact craters in the text is to highlight the consequence of the Moon lacking an atmosphere. The absence of an atmosphere on the Moon leaves it vulnerable to meteorite impacts, resulting in the multitude of impact craters on its surface. Choice A is incorrect because the mention of impact craters is not related to atmospheric weathering but rather to the lack of an atmosphere. Choice B is incorrect as it misinterprets the reason for the absence of plant life on the Moon. Choice D is incorrect as the text explicitly states that the Moon lacks tectonic or volcanic activity, which is not the focus of the mention of impact craters.

Correct Answer: D

Rationale: In the context provided, 'defective' means faulty, referring to the gene that causes cystic fibrosis (CF). The passage explains that CF is caused by a defective gene, resulting in the production of abnormally thick and sticky fluid. The word 'defective' suggests that the gene is not functioning correctly, leading to the symptoms associated with the disease. Therefore, 'faulty' is the correct choice. The other options, 'unusual,' 'remarkable,' and 'postponed,' do not accurately capture the meaning of 'defective' in this context and are therefore incorrect.