The TOEFL iBT® Reading Section is a crucial component of the TOEFL iBT® exam, assessing a test-taker's ability to comprehend and analyze written English material. This section consists of a passage, followed by a series of questions that test various reading skills. 

Taking practice tests can greatly aid in preparation for the TOEFL iBT® Reading Section. Practice tests simulate the format and difficulty level of the actual exam, allowing test-takers to become familiar with the types of passages and questions they will encounter.

Want to identify your strengths and weaknesses in the TOEFL iBT® Reading Section? Dive into this practice test on "Icebergs" and see how you improve!

Reading Instructions

• You have 15 minutes to read the following passage and answer all 10 questions related to it.  
• Most questions are worth 1 point, but the last question is worth more. The directions indicate how many points you will receive for that specific question. 
• The specific section/paragraphs have been provided again with the question for ease of understanding and quick solution.
• Some questions include a word or phrase that is highlighted in the question as well as in the paragraph for quick reference. 

Icebergs are enormous ice structures, often irregular in shape, with approximately 12 percent of their mass visible above the ocean surface. These formations originate from glaciers, and vast ice bodies originating inland from regions like Greenland, Antarctica, and Alaska. Gradually, they drift toward the sea, propelled by the glacier's forward motion and influenced by melting at its base where it interacts with the ocean. This process, coupled with wave action and tidal forces, leads to the detachment of ice blocks, which then float away into the open sea.

Icebergs generally exhibit shades ranging from blue to white, occasionally appearing dark or opaque due to embedded gravel and rock fragments. Their coloration may vary under different lighting and weather conditions, sometimes emitting pink or golden hues during sunrise or sunset. However, reports from travelers to Antarctica have highlighted unusual sightings of green icebergs, particularly in the Weddell Sea and near the Amery Ice Shelf in East Antarctica.

One theory proposes that the green tint of icebergs may result from an optical illusion when blue ice is illuminated by a low-angle red Sun, though green icebergs remain distinctive even in various lighting conditions. Another hypothesis suggests that the coloration could be linked to ice containing elevated levels of metallic compounds like copper and iron. Recent expeditions have collected ice samples from both green icebergs and ice cores extracted from the glacial ice shelves surrounding Antarctica. Analyzing these samples offers an alternative explanation for the phenomenon.

The ice shelf cores, spanning a total length of 215 meters (705 feet), extended deep enough to traverse through glacial ice, originating from compacted snow with air bubbles, and into the transparent, bubble-free ice formed from seawater freezing onto the underside of the glacial ice. The characteristics of this clear sea ice closely resembled the composition of the ice from the green iceberg. Consequently, scientists deduced that green icebergs are created when a two-layer section of shelf ice fractures and overturns, revealing the bubble-free shelf ice generated from seawater.

A green iceberg, found just west of the Amery Ice Shelf, displayed two distinctive layers: a frothy blue-white ice layer and a bubble-free green ice layer, separated by a one-meter-thick layer of ice containing sediments. The green ice section exhibited texturing from seawater erosion. In areas with cracks, the color appeared light green due to light scattering, while areas without cracks appeared dark green. Notably, the green ice lacked air bubbles, indicating its formation from seawater freezing rather than snow compression. Although high concentrations of single-celled organisms with green pigments inhabit the edges of ice shelves in this region, the green iceberg contained minimal organic particles from these organisms. However, it had accumulated dissolved organic matter from the seawater, suggesting that unlike salt, dissolved organic substances are not excluded during the freezing process. Analysis indicates that the absorbed blue wavelengths from solar light by the dissolved organic material contribute to the green appearance of the ice.

Chemical analysis reveals that platelets, small flat pieces of ice, initially develop in the water and subsequently adhere to the underside of the ice shelf, creating a slushy mixture due to partial snow melting. This slush undergoes compaction through an unidentified process, leading to the formation of solid, bubble-free ice originating from water-containing soluble organic compounds. Upon the iceberg's detachment from the ice shelf and subsequent overturning, the green ice becomes visible.

The Amery Ice Shelf seems especially conducive to the creation of green icebergs. After breaking away from the shelf, these icebergs are carried by the currents and winds encircling Antarctica, where they can be spotted mixed with the continent's more typical icebergs.

Directions: Once you have read the passage, answer the following questions.

Paragraph 1

Icebergs are enormous ice structures, often irregular in shape, with approximately 12 percent of their mass visible above the ocean surface. These formations originate from glaciers, and vast ice bodies originating inland from regions like Greenland, Antarctica, and Alaska. Gradually, they drift toward the sea, propelled by the glacier's forward motion and influenced by melting at its base where it interacts with the ocean. This process, coupled with wave action and tidal forces, leads to the detachment of ice blocks, which then float away into the open sea.

1. According to paragraph 1, all of the following statements about icebergs are true EXCEPT:
   1. They do not have a regular shape.
   2. They originate at the intersection of glaciers and the ocean.
   3. The majority of their mass extends beyond the sea surface.
   4. Breaking off glaciers is triggered by waves and tides.

Paragraph 2

Icebergs generally exhibit shades ranging from blue to white, occasionally appearing dark or opaque due to embedded gravel and rock fragments. Their coloration may vary under different lighting and weather conditions, sometimes emitting pink or golden hues during sunrise or sunset. However, reports from travelers to Antarctica have highlighted unusual sightings of green icebergs, particularly in the Weddell Sea and near the Amery Ice Shelf in East Antarctica.

1. According to paragraph 2, what leads to icebergs occasionally appearing dark or opaque?
   1. A heavy cloud cover
   2. Accumulated gravel or rock fragments
   3. The sun's low angle relative to the horizon
   4. The presence of large cracks in their surface

Paragraph 4

The ice shelf cores, spanning a total length of 215 meters (705 feet), extended deep enough to traverse through glacial ice, originating from compacted snow with air bubbles, and into the transparent, bubble-free ice formed from seawater freezing onto the underside of the glacial ice. The characteristics of this clear sea ice closely resembled the composition of the ice from the green iceberg. Consequently, scientists deduced that green icebergs are created when a two-layer section of shelf ice fractures and overturns, revealing the bubble-free shelf ice generated from seawater.

1. The term "traverse" in the passage is most similar in meaning to:
   1. penetrate
   2. explore
   3. examine
   4. extend

1. According to paragraph 4, how does glacial ice form?
   1. Through the compression of snow
   2. By freezing seawater on the underside of ice shelves
   3. Through detachment from the ice shelf
   4. By the overturning of a double-layered shelf ice block

1. According to paragraph 4, what did ice shelf cores reveal about the formation of green icebergs?
   1. The ice at the base of green icebergs is clear and bubble-free, originating from frozen seawater.
   2. Bubble-free ice is located at the uppermost part of the ice shelf.
   3. Glacial ice is lighter and has better buoyancy compared to sea ice.
   4. The clear sea ice underneath the ice shelf resembles the ice found in green icebergs.

Paragraph 5

A green iceberg, found just west of the Amery Ice Shelf, displayed two distinctive layers: a frothy blue-white ice layer and a bubble-free green ice layer, separated by a one-meter-thick layer of ice containing sediments. The green ice section exhibited texturing from seawater erosion. In areas with cracks, the color appeared light green due to light scattering, while areas without cracks appeared dark green. Notably, the green ice lacked air bubbles, indicating its formation from seawater freezing rather than snow compression. Although high concentrations of single-celled organisms with green pigments inhabit the edges of ice shelves in this region, the green iceberg contained minimal organic particles from these organisms. However, it had accumulated dissolved organic matter from the seawater, suggesting that unlike salt, dissolved organic substances are not excluded during the freezing process. Analysis indicates that the absorbed blue wavelengths from solar light by the dissolved organic material contribute to the green appearance of the ice.

1. Why does the author mention the statement that "The green ice section exhibited texturing from seawater erosion"?
   1. To clarify why cracks in the iceberg appeared light green instead of dark green.
   2. To imply that green ice is more susceptible to erosion by seawater than white ice.
   3. To bolster the notion that the green ice had originally formed as the bottom layer prior to capsizing.
   4. To elucidate the process by which air bubbles were eliminated from the green ice.

1. The term "excluded" in the passage is most similar in meaning to which of the following?
   1. Kept Out
   2. Pressed
   3. Harmed
   4. Collected

Paragraph 6

Chemical analysis reveals that platelets, small flat pieces of ice, initially develop in the water and subsequently adhere to the underside of the ice shelf, creating a slushy mixture due to partial snow melting. This slush undergoes compaction through an unidentified process, leading to the formation of solid, bubble-free ice originating from water-containing soluble organic compounds. Upon the iceberg's detachment from the ice shelf and subsequent overturning, the green ice becomes visible.

1. Which statement about the Amery Ice Shelf does the passage support?
   1. The Amery Ice Shelf exclusively generates green icebergs.
   2. Green icebergs from the Amery Ice Shelf result from its ice containing elevated levels of metallic compounds like copper and iron.
   3. Green icebergs from the Amery Ice Shelf stem from the seawater being abundant in a specific type of soluble organic material.
   4. Green icebergs are not typically found distant from the Amery Ice Shelf.

Paragraphs 2 and 3

Icebergs generally exhibit shades ranging from blue to white, occasionally appearing dark or opaque due to embedded gravel and rock fragments. Their coloration may vary under different lighting and weather conditions, sometimes emitting pink or golden hues during sunrise or sunset. (A) However, reports from travelers to Antarctica have highlighted unusual sightings of green icebergs, particularly in the Weddell Sea and near the Amery Ice Shelf in East Antarctica.

(B) One theory proposes that the green tint of icebergs may result from an optical illusion when blue ice is illuminated by a low-angle red Sun, though green icebergs remain distinctive even in various lighting conditions. (C) Another hypothesis suggests that the coloration could be linked to ice containing elevated levels of metallic compounds like copper and iron. (D) Recent expeditions have collected ice samples from both green icebergs and ice cores extracted from the glacial ice shelves surrounding Antarctica. Analyzing these samples offers an alternative explanation for the phenomenon.

1. Directions: Review the excerpt from the passage provided above. The letters (A), (B), (C), and (D) denote where the subsequent sentence could be incorporated.
   
   There has been debate among scientists regarding whether the green appearance of icebergs is due to light conditions or inherent characteristics of the ice itself.
   
   Where would the above sentence most appropriately belong?
   1. A) Choice A
   2. B) Choice B
   3. C) Choice C
   4. D) Choice D

1. Directions: You will find an introductory sentence for a summary of the passage provided below. Your task is to complete the summary by selecting the THREE answer choices that best represent the key ideas in the passage. Be mindful that some sentences may not align with the main ideas or may have minor points. This question carries a weight of 2 points.
   
   Various explanations, including factors such as light conditions and the existence of metallic compounds, have been proposed to account for the green hue observed in certain icebergs.
   
   
   •  
   •  
   •  

   Answer Choices

   1. Ice cores were used to determine that green icebergs were formed from the compaction of metallic compounds, including copper and iron.
   2. The Amery Ice Shelf is uniquely suited for producing green icebergs compared to other ice shelves.
   3. Green icebergs form when a two-layer block of ice breaks away from a glacier and capsizes, exposing the bottom sea ice to view.
   4. Ice cores and samples revealed that both ice shelves and green icebergs contain a layer of bubbly glacial ice and a layer of bubble-free sea ice.
   5. Green icebergs are initially white until they encounter seawater containing platelets and soluble organic green pigments.
   6. Sea ice in green icebergs contains substantial amounts of organic matter from the seawater.

Before moving forward to check your answers, don't forget to go through the updated TOEFL Exam Pattern and Syllabus. 

Answer Key with Explanation for TOEFL iBT® Reading Passage - Icebergs 

1.  Answer: C

Explanation: This is a Negative Factual Information question assessing specific details from paragraph 1. The accurate response is option C. The data provided in option C contradicts sentence 1, which indicates that icebergs "float with only about 12 percent of their mass above the sea surface." Conversely, the information in the remaining choices aligns with the details presented in the paragraph. 

2. Answer: B

Explanation: This is a Factual Information question aimed at specific details in paragraph 2. The correct answer is option B. This information is directly stated in sentence 1 of the paragraph, which mentions that icebergs can sometimes appear dark or opaque due to the presence of gravel and bits of rock. Options A, C, and D are incorrect because they do not accurately reflect the details presented in the paragraph.

3. Answer: A

Explanation: This is a Vocabulary question focusing on the word "traverse" highlighted in the passage. The correct answer is option A, "penetrate." In this context, "traverse" refers to the ability of ice shelf cores to penetrate or pierce through glacial ice. 

4. Answer: A

Explanation: This is a Factual Information question assessing specific details from paragraph 4. The correct answer is option A. The paragraph mentions that glacial ice is formed from the compaction of snow. Option B is incorrect because it describes sea ice, not glacial ice. Option C is inaccurate as it outlines the initial stage of green iceberg formation. Option D is also incorrect because it describes the subsequent step in green iceberg formation. 

5. Answer: D

Explanation: This is a Factual Information question aimed at specific details from paragraph 4. The correct answer is choice D. The paragraph mentions that clear sea ice is very similar to the ice found in green icebergs. Choices A, B, and C are incorrect. Choice A misinterprets the composition of green icebergs, while choice B contradicts the passage's information. Choice C introduces a concept not discussed in the paragraph. 

6. Answer: C

Explanation: This is a Rhetorical Purpose question aimed at understanding why the author mentions a specific detail in the passage. The correct answer is choice C. The highlighted sentence indicates that the green ice portion of the iceberg was once submerged in seawater, suggesting its origin and formation process. Choices A, B, and D are incorrect. Choice A provides factual information but does not address why the author includes the detail about seawater erosion. Choice B introduces a comparison not found in the passage, while choice D misinterprets the information about air bubbles in green icebergs. 

7. Answer: A

Explanation: This is a Vocabulary question. The word being tested is "excluded," highlighted in the passage. The correct answer is choice A, "kept out." In essence, dissolved organic substances are not kept out of the ice during the freezing process.

8. Answer: C

Explanation: This is an Inference question seeking an inference supported by the passage. The correct answer is choice C. Sentences 5, 6, and 7 in paragraph 5 provide evidence for this inference by explaining that the seawater surrounding these icebergs contains decomposing material from green-pigmented organisms. This material dissolves in seawater, which then freezes as part of the iceberg. Choice A is incorrect because paragraph 7 suggests that the Amery Ice Shelf is well suited for producing green icebergs, but it does not imply that it exclusively produces them. Choice B is inaccurate because copper and iron are mentioned in paragraph 3 only as potential sources of color in green icebergs, and other sources are mentioned later. Choice D is flawed because the passage does not specify the locations where all green icebergs can be found. The passage indicates that green icebergs can drift around Antarctica, not solely originate from the Amery Ice Shelf. 

9. Answer: B

Explanation: This is an Insert Text question where you are required to select the appropriate place to insert the provided sentence within the passage. Among the four possible answer choices provided in paragraphs 2 and 3, the sentence "There has been debate among scientists regarding whether the green appearance of icebergs is due to light conditions or inherent characteristics of the ice itself," is most fittingly inserted in choice (B).

Choice (B) is the correct answer as it appropriately introduces two possible explanations for the color of green icebergs. Paragraph 3 is the first place in the passage where explanations are offered for the color of green icebergs, making the beginning of paragraph 3 the most suitable location for introducing these possible explanations. 

Choice (A) is incorrect because green icebergs are mentioned for the first time in the last sentence of paragraph 2. Therefore, it wouldn't make sense to insert the given sentence, which introduces explanations for the color of green icebergs, before the first mention of green icebergs. 

Choice (C) is incorrect because its position is between the detailed discussions of the two explanations introduced in the given sentence. Since the given sentence introduces the two explanations, it must logically come before the discussions. 

Choice (D) is also incorrect because its position is after the detailed discussions of the two explanations introduced in the given sentence. Again, since the given sentence introduces the two explanations, it must logically come before the discussions. 

10. Answer: C, D, F

Explanation: This is a Prose Summary question, and the correct responses are C, D, and F. Therefore, options A, B, and E are incorrect.

Choice C: Choice C, “Green icebergs form when a two-layer block of ice breaks away from a glacier and capsizes, exposing the bottom sea ice to view,” is an accurate summary of paragraphs 4 and 5. These paragraphs explain that green icebergs are created when pieces of ice break off from an ice shelf and overturn, revealing the underlying sea ice. 

Choice D: Choice D, “Ice cores and samples revealed that both ice shelves and green icebergs contain a layer of bubbly glacial ice and a layer of bubble-free sea ice,” is a correct summary of the key information presented in paragraphs 3 and 4. These paragraphs detail how scientists analyzed ice cores and samples to determine the composition of ice shelves and green icebergs, revealing similarities in their structure. 

Choice F: Choice F, “Sea ice in green icebergs contains substantial amounts of organic matter from the seawater,” accurately summarizes the main point of paragraph 5, which discusses the presence of organic matter in the sea ice of green icebergs and its role in contributing to their green coloration. 

Choice A: Choice A, “Ice cores were used to determine that green icebergs were formed from the compaction of metallic compounds, including copper and iron,” is incorrect as it contradicts the information provided in the passage. Paragraph 3 mentions that metallic compounds were considered as possible causes of the green coloration of icebergs but were later disproved by analysis. 

Choice B: Choice B, “The Amery Ice Shelf is uniquely suited for producing green icebergs compared to other ice shelves,” is incorrect because the passage does not suggest that other ice shelves cannot produce green icebergs. It specifically mentions the Weddell Sea and the Amery Ice Shelf as locations where green icebergs are commonly found, but it does not exclude other ice shelves from producing them. 

Choice E: Choice E, “Green icebergs are initially white until they encounter seawater containing platelets and soluble organic green pigments,” is incorrect because the passage does not provide any information about the original color of green icebergs or their transformation upon encountering seawater. The passage focuses on various explanations for the green coloration of icebergs but does not mention any specific color changes.

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