TOEFL Reading Practice Test #15

Explanation: The correct answer is B). The passage states that technological advances have allowed scientists to explore deeper areas of the ocean, implying that earlier limitations in technology prevented these discoveries.

• A is incorrect because the passage mentions adaptations to the cold, not that it prevents life entirely.
• C is irrelevant since the focus is on the depths, not nutrient abundance at the surface.
• D contradicts the passage, which emphasizes the unique adaptations of deep-sea species.

Explanation: The correct answer is C). The passage highlights that bioluminescence evolved due to the absence of sunlight, which necessitated alternative adaptations.

• A is incorrect because bioluminescence is not an energy source but a method of attracting prey or mates.
• B is incorrect as the passage mentions prey attraction rather than mating.
• D is incorrect because the passage does not limit bioluminescence to predators only.

Explanation: The correct answer is C). The passage clearly states that organisms in hydrothermal vent ecosystems use chemosynthesis, converting chemicals like hydrogen sulfide into energy.

• A is incorrect because photosynthesis requires sunlight, which is absent at these depths.
• B is incorrect because it does not mention chemosynthesis.
• D is incorrect as the passage does not describe organisms absorbing heat directly.

Explanation: The correct answer is A). The mention of cold seeps serves to show the variety of unique ecosystems found in the deep ocean.

• B is incorrect because cold seeps do not rely on sunlight.
• C is incorrect because there is no comparison suggesting greater importance.
• D is incorrect because productivity is not discussed.

Explanation: The correct answer is D). The paragraph focuses on new technologies like ROVs and drones used for deep-sea exploration.

• A, B, and C are incorrect as they introduce ideas not mentioned in the paragraph.

Explanation: The correct answer is A). "Thrives" means to grow or develop well, especially in a favorable environment. In the passage, it refers to life forms that thrive in extreme conditions near hydrothermal vents.

• B, C, and D are incorrect because they imply poor growth or decline, which is the opposite of "thrives."

Explanation: The correct answer is B). The passage suggests that deep-sea ecosystems indicate life might exist in similar extreme environments elsewhere.

• A and C contradict the passage’s implication.
• D is irrelevant.

Explanation: The correct answer is D). The author discusses the excitement and potential of deep-sea exploration positively.

Explanation: The correct answer is B) because the sentence connects logically after describing cold seeps.

Correct Choices:

A) Deep-sea creatures have adapted to survive without sunlight by relying on alternative energy sources.
This option is correct because the passage discusses how deep-sea organisms, like the anglerfish, use adaptations such as bioluminescence or rely on chemical energy sources to survive in the absence of sunlight.

C) Hydrothermal vents support ecosystems that utilize chemosynthesis for energy.
This is a key point from the passage. It highlights the discovery of unique ecosystems near hydrothermal vents, where organisms like bacteria use chemosynthesis (sulfur-based energy generation) instead of photosynthesis.

D) Over 90% of the ocean remains unexplored, leaving many potential discoveries yet to be made.
This choice captures the idea that, despite technological advances, a large portion of the ocean remains uncharted. The passage emphasizes the vast unknown regions that hold the promise of future discoveries.

Incorrect Choices:

B) Most deep-sea species are very similar to those found near the ocean surface.
This is incorrect because the passage states the opposite: deep-sea species are often very different and have unique adaptations not seen in surface-dwelling marine life.

E) The bioluminescence of some deep-sea fish is a common feature of surface-dwelling species as well.
This option is incorrect because the passage specifically highlights bioluminescence as a unique adaptation of deep-sea creatures, not a common trait of surface species.

F) New technologies have significantly advanced our ability to explore the deep ocean and its hidden life forms.
This is correct because the passage discusses how advancements like ROVs and submersibles have enabled scientists to explore previously inaccessible parts of the ocean, leading to new discoveries.