The following text is from an article about ocean currents.
Ocean currents function like a global conveyor belt, distributing heat around the planet. Warm water from the equator flows toward the poles, while cold polar water sinks and moves toward the equator. This continuous circulation helps regulate Earth's climate and weather patterns.
What is the main purpose of the text?
To explain how ocean currents influence global climate
To argue for increased protection of ocean ecosystems
To describe the history of oceanographic research
To compare different types of marine environments
Correct Answer: A
Choice A is the best answer. The text explains how ocean currents work (conveyor belt, warm/cold water movement) and their role in regulating climate.
- Evidence: The text states currents "function like a global conveyor belt," describes water movement ("Warm water... flows... cold polar water sinks"), and notes the result ("regulate Earth's climate").
- Reasoning: The passage focuses entirely on the mechanism and function of these currents.
- Conclusion: The purpose is to explain this natural system and its influence.
💡 Strategy: Identify the main subject (ocean currents) and what the author says about it (how they work/what they do).
Choice B is incorrect because no argument for protection is made. Choice C is incorrect because research history is not discussed. Choice D is incorrect because marine environments aren't compared.