What is the passage primarily about?

Correct Answer: A

Rationale: The correct answer is A: 'What we know about the Moon and its differences from Earth.' The passage discusses various aspects of the Moon, including its origin, gravitational influence on Earth, physical characteristics, lack of atmosphere, and surface features. It provides insights into what humans know about the Moon and highlights its differences from Earth. Choice B is incorrect because while the passage does compare certain aspects of the Moon and Earth, it primarily focuses on the Moon itself rather than a direct comparison. Choice C is incorrect as the passage briefly mentions the Moon's effect on Earth in relation to tides but does not primarily focus on this aspect. Choice D is incorrect as the origin of the Moon is mentioned in the passage, but it is not the primary focus of the text.

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.

Correct Answer: C

Rationale: The correct answer is C. The paragraph is biased against people with piercing or harsh voices, suggesting they are less desirable as public speakers, newscasters, or political candidates. The text explicitly mentions that harsh voice qualities, like being shrill, grating, hard, piercing, brassy, loud, or nasal, are undesirable and may make people uncomfortable when speaking. It also highlights that tension leading to harsh voice qualities is more common in higher-pitched voices, which are typically associated with women, making them less preferred for public speaking roles. Choices A, B, and D are incorrect because the text does not suggest a balanced view, favor low-pitched voices, or maintain neutrality towards both high- and low-pitched voices; instead, it emphasizes the negative impact of harsh and piercing voices.

Correct Answer: D

Rationale: The correct analogy for the role of corrective lenses in helping aging eyes can be compared to an athlete stretching before a game. Just as stretching prepares an athlete's body to perform optimally and avoid injury during a game, corrective lenses help aging eyes adjust and focus properly due to the hardening and loss of elasticity in the eye lens. Choices A, B, and C do not align with the concept of preparing or adjusting to address a specific issue, unlike the use of corrective lenses for aging eyes.

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: In the context of the passage, 'massive' is used to describe the size of the collision that formed the Moon, indicating something very large or huge. While 'dense' means closely compacted, 'impressive' means evoking admiration, 'huge' is the closest synonym to 'massive' in this context. 'Unavoidable' does not convey the same meaning as 'massive' in this sentence, making it incorrect.

Correct Answer: B

Rationale: The correct answer is B. Matter at the nanoscale exhibits unique and special characteristics that distinguish it from matter at larger scales. This can include properties like increased surface area, different melting points, altered conductivity, and enhanced reactivity. Choice A is incorrect as metals at the nanoscale can be more rigid compared to their larger scale counterparts. Choice C is incorrect because matter at the nanoscale has properties that are distinct from both atomic and larger scales. Choice D is incorrect as there are significant differences in how matter behaves and interacts at the nanoscale compared to larger scales.

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: 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.