Correct Answer: B

Rationale: The correct answer is B: 'Water vapor plays a key role in precipitation.' The passage clearly outlines the importance of water vapor in the water cycle. It explains that water vapor returns to the air from surface water and plants, and condenses back into droplets of liquid, forming clouds. These clouds eventually lead to precipitation like rain, snow, sleet, or hail. Choice A is incorrect as water vapor is crucial in the water cycle. Choice C is also incorrect as there is no mention of water vapor being harmful in the passage. Choice D is incorrect as the passage does not state that water vapor cools the Earth's surface; instead, it highlights its role in the formation of precipitation.

Correct Answer: B

Rationale: The rainforest plays a crucial role in regulating the global climate by absorbing carbon dioxide. The extract highlights the fact that trees take in carbon dioxide and give off oxygen. When trees are cut down, the amount of carbon dioxide increases, contributing to global warming. This emphasizes the significant impact of rainforests on the climate. Choice A is incorrect as the extract clearly states the importance of rainforests in absorbing carbon dioxide. Choice C, while true, is not directly related to the implied role of rainforests in regulating the climate. Choice D is also incorrect as the destruction of rainforests does have global consequences, such as contributing to global warming.

Correct Answer: A

Rationale: The paragraph emphasizes that while food and drink are necessary and desirable, their abuse can lead to serious physical and mental problems. It highlights the negative consequences of overeating and alcohol abuse, such as strain on the heart, diabetes, and other health issues. The text suggests the importance of moderation in consumption to prevent health problems. Choices B, C, and D are incorrect because the paragraph does not call for a ban on alcohol, promote eating in large quantities, or specifically discuss the need for stronger laws to control drunk drivers.

Correct Answer: C

Rationale: The correct answer is C: 'To explain the tradition of giving white elephants.' The passage provides historical context about the practice of giving white elephants as gifts in ancient Siam, now Thailand. It explains how white elephants were considered sacred, could not be put to work, and became a burden to the recipients. The author's purpose is to shed light on this tradition and its implications, not to inform readers about Thailand in general (choice A), entertain with fun facts (choice B), or criticize the tradition (choice D). Choices A and B are incorrect because the passage focuses specifically on the tradition of giving white elephants, not on broader aspects of Thailand or entertainment. Choice D is incorrect because the passage does not criticize the tradition but rather provides a factual account of its historical significance.

Correct Answer: A

Rationale: Insomnia affects intellectual abilities by causing a deficit in memory, concentration, and attention. The passage highlights that lack of sleep impacts memory, attention, and concentration, leading to feelings of irritation or depression. Therefore, choice A is correct. Choices B, C, and D are incorrect because they do not align with the negative impact insomnia has on intellectual abilities as described in the passage.