The following text discusses ocean exploration.
We have mapped the surface of Mars more thoroughly than the ocean floor. Technological limitations long prevented detailed seafloor mapping at depths beyond a few hundred meters. Recent advances in autonomous underwater vehicles and multibeam sonar have revolutionized our capabilities. Scientists have discovered entire mountain ranges and volcanic systems previously unknown.
Which choice best describes the function of the first sentence?
It establishes a surprising comparison that highlights a knowledge gap.
It provides detailed statistics about Mars exploration.
It argues that Mars exploration should receive less funding.
It introduces the history of space telescopes.
Correct Answer: A
Choice A is the best answer. The Mars comparison establishes a surprising gap in our knowledge of Earth's own ocean floor.
- Evidence: The sentence states: "We have mapped the surface of Mars more thoroughly than the ocean floor."
- Reasoning: By comparing Earth's oceans to a distant planet, the author highlights the irony and extent of our ignorance about our own planet.
- Conclusion: The function is to establish a surprising comparison/gap.
💡 Strategy: Ask "Why mention Mars?" To show how little we know about Earth's oceans.
Choice B is incorrect because no detailed statistics are given. Choice C is incorrect because funding isn't discussed. Choice D is incorrect because telescopes aren't the topic.