Question 32·Medium·Central Ideas and Details
In northern Chile’s Atacama Desert, rainfall rarely exceeds 1 millimeter per year, yet small coastal villages survive thanks to “fog catchers.” These simple devices consist of tall meshes stretched between poles on misty ridges. Moisture-laden fog drifts through the mesh, condenses into droplets, and trickles into gutters leading to storage tanks. Engineers visiting the region once dismissed fog catchers as quaint but inefficient. Current studies, however, reveal that a single 50-square-meter net can collect up to 400 liters of water on a humid morning—enough to irrigate crops and supply drinking water for dozens of households. As a result, environmental groups now promote fog catchers as a low-cost, sustainable solution for communities facing water scarcity.
According to the passage, why have environmental groups begun to promote fog catchers?
For "According to the passage" questions, go straight to the part of the passage that mentions the key word or phrase from the question (here, "environmental groups"), then read one or two sentences around it to catch any cause-and-effect signals like "as a result" or "because." Paraphrase the reason in your own words first, then compare that paraphrase to the answer choices, eliminating any option that introduces details the passage never mentions, even if they sound reasonable. Always choose the answer that is directly and fully supported by the text, not just loosely related.
Hints
Find where environmental groups are mentioned
Skim the passage and locate the sentence that talks about environmental groups. The reason you need is likely in that sentence or right before it.
Pay attention to cause-and-effect words
Notice the phrase "As a result" in the sentence about environmental groups. Ask yourself: a result of what? Look at the sentence immediately before it.
Identify the key new information before "As a result"
In the sentence before "As a result," what do the current studies show about fog catchers? Think about why that information might convince people to support them.
Check each choice against the passage
For each answer choice, ask: Does the passage clearly say this? Eliminate any choice that introduces new ideas (like materials used, aid requests, or scientific research goals) that are not mentioned.
Step-by-step Explanation
Understand what the question is asking
The question asks: "According to the passage, why have environmental groups begun to promote fog catchers?" This means you must find the specific reason stated in the passage, not use outside knowledge or personal opinions.
Locate the part of the passage about environmental groups
Scan for the phrase "environmental groups" in the passage. It appears near the end: "As a result, environmental groups now promote fog catchers as a low-cost, sustainable solution for communities facing water scarcity." The phrase "As a result" tells you that the reason comes from the information in the previous sentence.
Identify what "As a result" refers to
Look at the sentence right before: "Current studies, however, reveal that a single 50-square-meter net can collect up to 400 liters of water on a humid morning—enough to irrigate crops and supply drinking water for dozens of households." This shows that new research has proved fog catchers can collect a large amount of usable water, making them effective for irrigation and drinking in water-scarce areas.
Match that reason to the answer choices
Now compare this idea to the options. Only one choice says that environmental groups promote fog catchers because recent research shows they can collect a lot of water, making them a practical solution to water shortages. That matches the cause-and-effect relationship described by "Current studies..." and "As a result", so the correct answer is: Because recent research shows that fog catchers can collect significant amounts of water, making them a practical solution to water shortages.