The following text discusses renewable energy storage.

Battery technology remains a bottleneck for renewable energy adoption. Solar and wind power generation fluctuates with weather conditions, requiring storage to ensure consistent supply. Lithium-ion batteries dominate current markets but face material scarcity and disposal challenges. Researchers are exploring alternatives including solid-state batteries, hydrogen fuel cells, and even gravity-based storage systems.

6
reading

Which choice best describes the function of the first sentence?

A

It establishes the central problem that the rest of the passage addresses.

B

It provides a comprehensive history of battery development.

C

It questions whether renewable energy is actually beneficial.

D

It compares different types of battery chemistry in detail.

Correct Answer: A

Choice A is the best answer. The first sentence identifies storage as a "bottleneck"—the central problem that the passage then elaborates on.

  1. Evidence: The sentence states: "Battery technology remains a bottleneck for renewable energy adoption."
  2. Reasoning: The term "bottleneck" signals a problem or obstruction. The rest of the text explains why (fluctuation) and what is being done (alternatives).
  3. Conclusion: The function is to establish the central problem.

💡 Strategy: Focus on the keyword "bottleneck" -> implies a problem to be solved.

Choice B is incorrect because no history is provided. Choice C is incorrect because renewable benefits aren't questioned. Choice D is incorrect because detailed comparison comes later.