Question

The following passage is adapted from an article about deep-sea oceanography.

Paragraph 1 (lines 1-10)
In 1977, oceanographers aboard the research vessel Alvin made a baffling discovery along the Galapagos Rift, thousands of meters below the ocean surface. Expecting to find a biological desert due to the complete absence of sunlight and near-freezing temperatures, scientists were instead confronted with a thriving, dense community of previously unknown organisms, including giant tube worms and ghost-like crabs. This startling find shattered the long-held scientific assumption that all complex marine life ultimately depends on solar energy filtered down from the upper layers of the ocean.

Paragraph 2 (lines 11-19)
At the heart of this deep-sea ecosystem lay hydrothermal vents—geological fissures that spew superheated, mineral-rich water from beneath the Earth's crust. As this fluid mixes with the cold seawater, minerals precipitate out, forming chimney-like structures. Oceanographers quickly realized that these vents act as vital heat and chemical conduits, transferring thermal energy from the planet’s mantle into the ocean depths, thereby maintaining localized temperatures that can support life.

Paragraph 3 (lines 20-29)
Subsequent microbiological analysis revealed that the biological engine driving this ecosystem was not photosynthesis, but chemosynthesis. Specialized bacteria, dwelling inside the tissues of the tube worms or forming mats on surrounding rocks, oxidize toxic hydrogen sulfide escaping from the vents. By converting these chemical compounds into organic matter, these microbes form the foundational base of the local food web, proving that life can flourish entirely independent of sunlight.

Match each paragraph from the passage to its primary paragraph-level main idea.